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shullyWave FormsAIR2390Wave Forms

Waves are disturbances of energy that occur all around us, all of the time. Examples of waves include ripples in water, hand waves, and even sound and light. Let's find out what makes them tick.

http://phet.colorado.edu/sims/html/wave-on-a-string/latest/wave-on-a-string_en.htmlhttp://www.animatedscience.co.uk/blog/wp-content/uploads/focus_waves/programme-assets/swf/translongwaves.swfTransverse WavesLongitudinal Waves

Setup Directions: Select "Oscillate" in the top-left toolbox, "No End" in the top-right toolbox, and slide the "Damping" slider all the way to the left in the bottom toolbox.

In the window to the right you should see a wave rippling. This type of wave is called a Transverse wave, because each of its segments MOVE VERTICALLY to the motion of the wave. Hence, the word Trans- (to move) Verse (vertically, or against). As the wave progresses from left to right, each of the little beads moves up and down perpendicularly to the direction the wave travels. Follow the activity below, answer the questions, and then move on to Longitudinal Waves.

Setup Directions: Select "Longitudinal" in the toolbox, and press the play button.

Longitudinal waves are also referred to as "compression" waves. Notice how the segments moving in the wave to the right COMPRESS together along the longitudinal axis of the wave. The segments or particles being disturbed by a compression wave move parallel to the direction the wave is moving. Follow the activity below, answering all questions. Press the PRINT button when you complete all of the questions.

0textRead the Transverse Waves introduction in the upper-lefthand corner of the screen.

Observe the transverse wave. Look closely at how the particles move up and down, yet the wave moves to the right.1actionSlide the "Amplitude" bar left, and then right (but not all the way to the right). Observe what happens to the wave.2responseDescribe what a wave's amplitude is. Try to put your description in definition form.3actionSlide the "Frequency" bar left, and then right. Observe what happens to the wave.4responseAs frequency increases, what happens to the wave?5responseIs the wave moving faster, slower, or at the same speed? Defend your response. (Try counting how long it takes the top of the wave to travel from the left side to the right side)6actionSelect "Pulse" in the top-left toolbox instead of oscillate. Press the green button to create a pulse wave. Move the frequency bar mostly to the left, create a pulse wave, and then to the right, and create another pulse wave.7responseDoes your response to the last question change? (In other words, does frequency affect the SPEED of the moving wave?)0textRead the Longitudinal Waves introduction in the upper-lefthand corner of the screen.

Observe the Longitudinal wave. Look closely at how the particles from side to side, and how the wave moves to the right.1actionPress the PAUSE button. Observe the segments of the wave. Press PLAY, increase the amplitude, and then press the STOP button again after you have observed the new wave.2responseHow is increasing a Longitudinal Wave's amplitude similar to increasing a Transverse wave's amplitude? How is it different?5responseA guitar uses vibrating strings to produce sound, and sound is an example of a longitudinal wave. What do you think will happen to the pitch of a note played by a guitar if the string's frequency of vibration is increased? Explain.7responseHow does this compression pulse wave compare to a transverse pulse wave?shullyDoppler EffectIR3300Doppler Effect

The doppler effect is a wave phenomena that occurs when a stationary observer encounters waves produced from a moving source. As the the moving wave source approaches the observer, the frequency of the wave produced by the moving source is observed to be higher than if the wave source was stationary. Also, as the moving wave source moves away from the stationary observer, the observed frequency is less.

A car passing by a pedestrian is probably the most common of the doppler effect. Whether the car's engine is the only thing producing sound or the car's horn is engaged, the stationary pedestrian "observer" will hear a high frequency sound as the vehicle approaches followed by a lower frequency sound as it departs. Hear It

Procede through the activities below to explore the doppler effect.

http://www.walter-fendt.de/html5/phen/dopplereffect_en.htmhttp://www.tandftechnology.com/Physics/Programs/Labs/DopplerLab/index.htmlhttp://astro.unl.edu/classaction/light.htmlAmbulance SirenApproaching Mach 1Comparing Stationary & Moving Sources

Set-up: After Java doesn't run, scroll down a little and click "Java Application". After it downloads, run it ("Open" in Internet Explorer, or in Chrome, click on the download at the bottom of the browser). Reposition the simulation window over the Activity space to the right.

The growing circles represent sound wave "compression" areas or wave crests as the sound from the siren travels away from the ambulance. Just because the ambulance is moving does not mean the waves "move" along with it. Waves travel from the point in space where they are created, and can only move as fast as the medium they are travelling through will allow them; in this case, sound travels through the air, so sound is limited to moving as fast as sound travels in the air. Sound travels at about 770 mi/hr through air, but even if the ambulance is moving at 30 mi/hr, sound will still travel outward from its source at 770 mi/hr. It will not travel at 800 mi/hr just because the ambulance is moving.

Make observations and record your responses to this activity in the box below.

The moving object represents a moving sound source traveling at Mach 0.43. If the dot is an aircraft, that means that it is traveling at 43% of the speed of sound. (The speeds at the bottom of the screen represent 10s of miles per hour; the speed of sound is roughly 700 miles per hour, so if the aircraft is set at 30, then its speed is 300 mph. 300/700 = Mach 0.43)

The growing circles eminating from the sound source, as in Activity 1, represent wave fronts. This simulation allow us to see how aircraft approaching the speed of sound create an intense "wall" of compressed air that is commonly called the sound barrier.

Introduction:

In this simulation, the top wave is produced by a wave source, and the bottom wave is what the observer of the wave receives. The wave could represent not only sound, but also light.

Doppler Effect on light - Redshift and Blueshift:

Activities 1 and 2 are based on waves created in the air through compressions, called longitudinal waves. The wave "fronts" represented the highly compressed regions of air as sound was produced and traveled through the air. In this activity, you are given a view of transverse waves and how they travel after being emitted by moving and stationary sources.

Light has wave-like properties that can be describe using transverse waves. Studying light waves from stars, galaxies, and other formations is the only way astrophysicists can discover information about them. In particular, by looking at the wavelengths of light emitted by a star, scientist is able to observe redshift and blueshift. Redshift and blueshift are the result of the Doppler effect applied to light waves. If light from a particular star is redshifted, the observed wavelengths of light are greater than they should be, making the light appear more toward the red end of the visible light spectrum. If light from a particular star is blueshifted, the observed wavelengths of light are less than they should be, making the light appear more toward the blue end of the visible light spectrum:

0textRead the Activity 1: Ambulance Siren introduction in the upper-lefthand corner of the screen.

Observe the ambulance and the sound waves produced. Look closely at how the waves hit the observer as the ambulance approaches, and as the ambulance passes and departs.1actionPress the "Start Again" button and count how many wave fronts hit the observer as the ambulance approaches, and count how many wave fronts hit the observer as the ambulance departs (stop counting after the ambulance leaves the screen).2responseHow many wave fronts impact the observer on approach? 3responseHow many wave fronts impact the observer on departure (stop counting after the ambulance leaves the screen)?4responseIs the sound wave's frequency greater as the abulance approaches the observer, or as it departs? Explain your reasoning.5actionThe wave fronts impact the observer for 10 seconds as the ambulance approaches and 20 seconds as the ambulance departs. Calculate the frequency of the sound on approach and departure using your counts from your first two responses above. (f = [# of waves] / time)6responseReinforce your reasoning from response #3 with the numerical values of frequency that you've just calculated to explain how sound frequency changes on approach and departure.0textRead the introduction to Activity 2. Press "Begin" and "Start" the simulation.1actionView the moving sound source as it moves at 300 mph, or Mach 0.43, which is 43% of the speed of sound in air.2responseIf this sound source were an aircraft originating west of you and passing overhead while traveling east, you would hear the sound coming from it's engines. Describe what you would probably hear as it approaches from the west, passes directly over your head, and departs to the east.3action"End" the simulation, and then increase the "object speed" by increments of 10, starting the simulation after each increment change so that you can observe the changes occurring between each increment. At this point, do not go higher than a speed of 50.4responseDescribe what happens to the sound wave fronts as the object's velocity is increased.5actionIncrement the velocity ratio slider to 60 (Mach 0.86), and then to 70 (Mach 1, the speed of sound), observing the resulting waves at each increment.6responseWhen an aircraft is traveling at Mach 1 it is said to have reached the "sound barrier". Explain why this phrase is used to describe Mach 1.7responseWhen the sound barrier is reached by an aircraft, observers on the ground experience an extremely loud "bang" sound, which is powerful enough to make houses shake and dishes to fall off of tables. Explain this phenomenon based on what you see in the animation.0textIn the Activity window/tab: (If Flash is not enabled, click the website screen to enable Flash.) Click the "Animations" tab and then click "Doppler Shift Demonstrator." Read the introduction to activity 3.1actionPress the "start emission" button, and increase the "rate" slider bar to the right, all the way to its maximum. Allow the wave fronts to hit the "O" object, the observer. Observe how the "waves as emitted from source" and the "waves as detected by observer" move up and down (vertically) at the same rate.4textThis demonstrates that both wave sources are the same; the waves that they produce are only different because one wave source is in motion while the other is stationary.6actionClick and hold the mouse button over the "S" object - the source - and drag it toward the observer object, "O"7responseWhat happens to the wavelength of the observer's "detected" wave as the source's velocity increases toward the observer?8actionClick and hold the mouse button over the "S" object - the source - and drag it away from the observer object, "O"9responseWhat happens to the wavelength of the observer's "detected" wave as the source's velocity increases away from the observer?10responseDescribe how this wave simulation confirms our earlier observations that a moving sound source creates a different frequency of sound compared to a stationary sound source.11textRead the Redshift and Blueshift section of Activity 3's information area to the left.13actionMove the source toward the observer. This would be an example of how blueshift is created.

Move the source away from the observer. This would be an example of how redshift is created.14responseIf an astronomer determines that light from a star appears to be redshifted (wavelengths of visible light are greater than they should be), what can he/she determine about the motion of that star relative to the Earth? Defend your response.shullyConservation of Momentum: Crash CartsAI11320Conservation of Momentum: Crash Cartshttp://www.walter-fendt.de/html5/phen/collision_en.htmCart Collisions

Directions - Refer to the graphic below for help

Read the introduction to the Elastic/Inelastic Collisions Java Applet.
In the upper right-hand corner of the applet you will see a selection for Elastic collisions and Inelastic collisions. Select Elastic or Inelastic, depending upon the situation.
In the bottom right-hand corner of the applet you will see a selection for Velocity, Momentum, and Kinetic Energy. Use these selections to help check your work.

Problems
The purpose of this exercise is two-fold: to explore the uses of technology for use in your studies, and to check your work on more involved momentum problems. For each problem below, YOU may select the masses of the two simulated collision carts, between 0.1 and 1.0 kg. Also, select a speed, for cart 1 (v1) in the range of 0.1 to 0.5 m/s, and a speed for cart 2 (v2) in the range of ?0.5 to 0.4 m/s. After selecting the values, solve the problem. Then, plug your values into the Applet and check your answers!

Problem 1: Inelastic collision of two carts
Select "Inelastic Collision" in the top-right corner of the applet. Select masses and initial velocities for the two carts that will have an inelastic collision, and solve for their final velocity and the amount of lost kinetic energy. When you are finished, check your work using the momentum applet.

Problem 2: Elastic collision, head-on
Select "Elastic Collision" in the top-right corner of the applet. Select masses and initial velocities for two carts that will have an elastic collision, making sure that the velocity of cart 1 is positive and the velocity of cart 2 is negative. Solve for their final velocities.

If you haven't learned how to solve systems of equations in algebra, plug in one of the values from the applet labeled "Velocities after the collision" and solve for the velocity value to check your work; otherwise, follow the instructions below.

Solving with systems of equations: This situation is more complicated than you are used to. You will have to apply the law of conservation of momentum AND the law of conservation of (kinetic) energy to solve a system of two equations with two unknowns. When you are finished, check your work using the momentum applet.

Problem 3: Elastic rear-end collision
Select masses and initial velocities for two carts that will have an elastic collision, making sure that the velocity of cart 1 is positive and the velocity of cart 2 is positive. Solve for their final velocities. This situation is similar to that of problem 2. When you are finished, check your work using the momentum applet.

Questions:

How does a vehicle?s velocity (speed and direction) affect the results of a collision?
How does a vehicle?s mass affect the results of a collision?
How do elastic and inelastic collisions differ?

shullyPhET: Geometric OpticsAR1300PhET: Geometric Opticshttp://phet.colorado.edu/sims/geometric-optics/geometric-optics_en.htmlConverging Lenses0textIn this activity you will be able to observe dynamically-constructed ray diagrams and discover the changes to the image as the object is moved around to different positions.1actionSet up the display by making the following changes to the options and sliders in the green tool box at the top of the screen:

Select "Principal rays"
Slide the "refractive index" slider all the way to the right
Slide the "diameter" slider all the way to the right
Check the "virtual image" checkbox
If you want to change the picture of the object, do so.

2textYou will notice two "X" marks positioned at equal distances on either side of the lens where two of the principal rays pass over the principal axis. These are the focal points. The distance from the lens to one of these focal points is called the focal length.3actionMove the object so that it is at a position twice the focal length ( 2f ) away from the lens so that the focal point on the left side of the lens is directly in the middle between the object and the lens.4responseHow does the distance from the lens to the image compare to the distance from the lens to the object? How does the height of the image compare to the height of the object? How does the orientation (upright or inverted) of the image compare to that of the object? Sum up your response to these three questions by completing this sentence: When an object is placed in front of a lens at a distance of twice the lens's focal length, the image will appear...5actionSlide the object backward along the principal axis. Observe the changes to the image.6responseDescribe what happens to the height and position of the image as the object is moved away from the lens.7actionReturn the object to the 2f position (twice the focal length from the lens). Now, slowly slide the object toward the focal point. Do not move it past the focal point yet. Observe the changes to the image.8responseDescribe what happens to the height and position of the image as the object is moved toward the focal point.9actionSlide the object toward the lens so that it is inside the focal length. Observe the changes to the image.10responseDescribe what happens to the height and position of the image while moving the object around inside the focal length.11textSum up!12responseWhere can the object be placed so that the image is enlarged?13responseWhere can the object be placed so that the image is reduced?14responseWhere can the object be placed so that the image is inverted?15responseWhere can the object be placed so that the image is upright?shullyNuclear Fusion and Stellar ClassificationAIR3230Nuclear Fusion and Stellar ClassificationLike many other things big and small, stars are born, they live, and they die. Some stars are of unbelievable size and magnificent, others seem small and ordinary. Some stars go out with a bang. What makes them all unique? What fuels their magnificent fires? All the questions we have about stars may never be answered, but the nature of nuclear fusion reactions offer some significant insight into answering at least some of them.https://shullyphysics.com/Apps/Drop-in%20Creator/Sites/site3/Energy Generation in Stars - STARBASE.htm?Original=http://www.ph.surrey.ac.uk/astrophysics/files/energy_generation_in_stars.html#nuclearhttps://shullyphysics.com/Apps/Drop-in%20Creator/Sites/site1/Types of Stars.htm?Original=http://www.atnf.csiro.au/outreach/education/senior/cosmicengine/stars_types.htmlhttps://shullyphysics.com/Apps/Drop-in%20Creator/Sites/site2/Classifying Stars - The HR Diagram.htm?Original=http://www.atnf.csiro.au/outreach/education/senior/cosmicengine/stars_hrdiagram.htmlFusion Reaction Equations and the Energy ReleasedTypes of Stars and Their FuelHertzsprung-Russell Diagrams

This website presents information about nuclear fission and fusion, and describes how atomic nuclei fuse with other nuclei during fusion reactions in stars. You will learn about the Proton-Proton cycle that takes place in our own star - the Sun - as well as the C-N-O cycle (carbon - nitrogen - oxygen) that takes place in star that are larger than our own.

You will begin reading this webpage under the gold The Nuclear Atom - Fission and Fusion heading.

In the last activity, you were able to see two fusion cycles that occur in stars of different size. Larger stars fuse even heavier elements, such as Silicon-28 with Helium-4.

As you scan through this document, you will see most of the different classifications of stars in our universe. In general, you will observe that the bigger stars burn heavier elements.

The Hertzsprung-Russell Diagram places all the known stars on a graph according to their Luminosity and Effective Temperature.

The diagram reveals that stars tend to group together, and the likely cause is their size and types of fusion reactions occurring in their cores

On many HR-Diagrams, other information about the stars is labeled too, but luminosity vs. temperature are the main quantities described.

All luminosities are compared to that of our Sun, so our Sun has a luminosity of "1" and a star 100 times brighter has a luminosity of "100."

The "Effective Temperatures" do not refer to the core temperatures discussed earlier in this activity that are required for fusion, so do not be confused by that.

Look carefully! The luminosities are sometimes labeled on the left side of the diagram, and sometimes on the right side. Temperature can be found at the top or at the bottom of the diagram, and it is not labeled in the standard fashion for a graph! Values of temperature increase from left to right.

0actionRead quickly through the first two paragraphs under the gold The Nuclear Atom - Fission and Fusion heading (it is not necessary to take in all this information).1responseWhat fundamental physical force is the source of the binding energy of an atomic nucleus?2actionStudy the axes of the Binding Energy per Nucleon graph, and read the paragraph that follows.3responseWhat element has the most stable nucleus due to its incredibly high binding energy?4actionRead the next paragraph on nuclear fission.5responseWhy is nuclear fission possible only for elements of higher mass number than iron, such as uranium?6textWhen the temperature of matter increases (gets hotter), its molecules move faster and become more energetic. That is why even though the outside of a hot metal cooking pot looks the same as when it is cold, it can burn your skin when you touch it. The shape of the pot does not change, but its atoms are vibrating faster when it is hot compared to when it is cold. So, when your skin contacts the hot, quickly-vibrating metal atoms on the pot, your skin cells are violently "shaken up" and are killed.7actionRead the next paragraph on nuclear fusion.8responseWhat does the intense gravitational force do to the temperature near the center of a star?9responseAs the temperature of the star changes in this way, what will happen to the speed of the protons and other matter at the center of the star?10responseDescribe how the speed of two protons helps them to fuse together in a star.11actionRead the remainder of the section (until you reach the "Links") to learn about how energy is released in this fusion reaction.12actionScroll down to the Proton Cycle section, and read it.13textThis section indicates that fusion of hydrogen requires a stellar core temperature of at least 8 x 10⁶ K. K is short for Kelvin, which is a unit of temperature. In this case, Kelvin is very similar to degrees Celsius. If you are sitting in an air-conditioned or heated room right now, the room probably has an air temperature of about 20-22 degrees Celsius. 14responseIn standard number form, what is 8 x 10⁶ degrees of temperature equal to? (in other words, what is this number expanded out, without the 10^ exponent?)15actionLook carefully at the Proton-Proton cycle fusion reaction equations. The first two equations depict the fusion reaction of different hydrogen isotopes along with the energy each reaction releases (which of course, creates more heat in the star). The unit MeV stands for "mega electron-volt", and is a measure of energy for moving electrons.16responseOur star, the Sun, "burns" hydrogen to produce its energy. How much total energy (in MeV) is produced from the two reactions? This is the energy produced by the fusion of Hydrogen in the Sun.17actionRead about the C-N-O cycle of carbon, nitrogen, and oxygen.18responseCompared to our Sun, what kind of star "burns" C, N, and O in its fusion reactions?19responseWhat is the total amount of energy produced by these C-N-O fusion reactions? 0actionScroll down to the "Main Sequence Stars" section to begin. Read the 2 introductory paragraphs, and look at the fusion reaction diagram for Proton-Proton fusion. This diagram represents the nuclear fusion reactions of various forms of Hydrogen and Helium. 1responseFollow the reaction starting from the top-left of the diagram. When a hydrogen ¹H and another ¹H react, what is the new ²H made up of? (FYI, ²H is called deuterium)? 2responseWhat does the ²H then react with to produce a helium ³He? 3responseFinally, when two helium ³He nuclei undergo a fusion reaction, what are the three products?

These 3 steps are the 3 fusion reactions that occur in stars like our Sun, which produce all of their energies, heat, light, and radiations. 4actionRead through the next 4 brief paragraphs (before the "Key Properties" table) and respond to the questions below, which relate to the 4 paragraphs. 5responseHow much mass, compared to our Sun's mass, does a star require to start hydrogen fusion?6responseIf a protostar (a massive object that can possibly become a star) has less than this minimum amount of mass, what does it become?7responseIf a star is significantly more massive than our Sun, describe its probable luminosity and lifespan compared to our sun.8responseStudy the Key Properties of Main Sequence Stars chart. Consider a main sequence star that is 60 times more massive than our Sun. How many times more bright is this star compared to our Sun?9actionNow, take a look at the "Red Giants". Read through this section as you respond to the questions below.10responseIn what part of a red giant star does hydrogen burning take place?11responseIs the temperature of a red giant star greater or lesser than it was when the star was a main sequence star?12responseHow much larger might a main sequence star like our Sun become when hydrogen burning in its core ceases?13actionRead briefly through the "Supergiants and Supernovae" section.14responseIn one sentence of your own words, sum up how heavier elements up to Iron are created within supergiants. 15responseThis section of the article refers to Nucleosynthesis. Take the word apart: What does Nucleo- refer to?16response"Synthesis" refers to a "combination." Therefore, what does the process of nucleosynthesis in stars describe? 17responseComplete the sentence in your own words: A supernova is the result of a supergiant _______.18actionRead briefly through the remainder of the article, covering White Dwarf stars, Neutron stars, and Black Holes.19responseComplete the sentence in your own words: A White Dwarf star is a star that was once like our own Sun, but has _______.20responseA Neutron star is what often remains after a supernova. If we had one teaspoonful of the neutron star's unique "neutron matter" here on Earth, about how many tons would it weigh?21textThis article explains that a Black Hole is formed after a super-massive supergiant goes supernova (a lot of super-s), and the remaining neutron matter is packed into an extremely small volume for that amount of matter. The maximum distance radius required for a particular amount of mass to be compacted to form a Black Hole is called the Schwarzchild radius, and it depends mainly on just the mass of the object. You can calculate your own Schwarzchild radius; if all of your mass was packed into this radius, you would become a Black Hole. Calculate it!

Your Mass = [your weight in pounds] / 2.2

R_Sch = (1.48 x 10^-27) * Mass22responseWhat is your Schwarzchild radius?23responseWhat is the Schwarzchild radius of our Sun? (m_sun = 1.99 x 10³⁰ kg)0actionSkip the reading for now (you may read at your leisure later) and scroll down to the "Axes of H-R Diagram" graph.1responseDo luminosities of stars increase on the H-R diagram from "bottom to top", or from "top to bottom"?2responseDo temperatures of stars increase on the H-R diagram from "left to right", or from "right to left"?3actionScroll down to the first Hertzsprung-Russell Diagram with the letters A, B, C, D labeled on it.4responseWithout peeking at other H-R diagrams or reading further, in which group of stars plotted on the diagram (A, B, C, or D) do you think main sequence stars can be found?5responseWhere do think the nuclear fuel-spent White Dwarf stars might be found (A, B, C, or D) on the diagram?6responseWhere do think Red Giant stars might be found (A, B, C, or D) on the diagram?7responseWhere do think the Super Giants might be found (A, B, C, or D) on the diagram?8actionScroll down to the next H-R diagram that is colored from Blue to Red. Were your guesses accurate (no need to change your responses if they were wrong)9responseFind our star, the Sun, within the Main Sequence group. Now, find the star Sirius B. Compare our Sun's luminosity and temperature to this white dwarf star:10responseWhich star has a temperature of over 7000 K and a luminosity of about 10,000 times that of our Sun? (Remember, 10,000 = 10⁴)11responseWhich is the coldest star plotted on this diagram?12responseWhich is the brightest star plotted on this diagram?13responseWhich star has a temperature of about 22,000 K and a luminosity of about 1,000 times that of our Sun?14actionSee how well you understand H-R diagrams! Take the Star Classification Quiz. Just make sure that you return to this page to print your responses. shully Nuclear Fusion and Stellar Classification PWA AIR 3 230 Nuclear Fusion and Stellar Classification Like many other things big and small, stars are born, they live, and they die. Some stars are of unbelievable size and magnificent, others seem small and ordinary. Some stars go out with a bang. What makes them all unique? What fuels their magnificent fires? All the questions we have about stars may never be answered, but the nature of nuclear fusion reactions offer some significant insight into answering at least some of them. https://shullyphysics.com/Apps/Drop-in%20Creator/Sites/site1/Types of Stars.htm?Original=http://www.atnf.csiro.au/outreach/education/senior/cosmicengine/stars_types.html https://shullyphysics.com/Apps/Drop-in%20Creator/Sites/site2/Classifying Stars - The HR Diagram.htm?Original=http://www.atnf.csiro.au/outreach/education/senior/cosmicengine/stars_hrdiagram.html Types of Stars and Their Fuel Hertzsprung-Russell Diagrams

In the last activity, you were able to see two fusion cycles that occur in stars of different size. Larger stars fuse even heavier elements, such as Silicon-28 with Helium-4.

As you scan through this document, you will see most of the different classifications of stars in our universe. In general, you will observe that the bigger stars burn heavier elements.

The Hertzsprung-Russell Diagram places all the known stars on a graph according to their Luminosity and Effective Temperature.

The diagram reveals that stars tend to group together, and the likely cause is their size and types of fusion reactions occurring in their cores

On many HR-Diagrams, other information about the stars is labeled too, but luminosity vs. temperature are the main quantities described.

All luminosities are compared to that of our Sun, so our Sun has a luminosity of "1" and a star 100 times brighter has a luminosity of "100."

The "Effective Temperatures" do not refer to the core temperatures discussed earlier in this activity that are required for fusion, so do not be confused by that.

0actionScroll down to the "Main Sequence Stars" section to begin. Read the 2 introductory paragraphs, and look at the fusion reaction diagram for Proton-Proton fusion. This diagram represents the nuclear fusion reactions of various forms of Hydrogen and Helium. 1responseFollow the reaction starting from the top-left of the diagram. When a hydrogen ¹H and another ¹H react, what is the new ²H made up of? (FYI, ²H is called deuterium)? 2responseWhat does the ²H then react with to produce a helium ³He? 3responseFinally, when two helium ³He nuclei undergo a fusion reaction, what are the three products?

These 3 steps are the 3 fusion reactions that occur in stars like our Sun, which produce all of their energies, heat, light, and radiations. 4actionRead through the next 4 brief paragraphs (before the "Key Properties" table) and respond to the questions below, which relate to the 4 paragraphs. 5responseHow much mass, compared to our Sun's mass, does a star require to start hydrogen fusion? 6responseIf a protostar (a massive object that can possibly become a star) has less than this minimum amount of mass, what does it become? 7responseIf a star is significantly more massive than our Sun, describe its probable luminosity and lifespan compared to our sun. 8responseStudy the Key Properties of Main Sequence Stars chart. Consider a main sequence star that is 60 times more massive than our Sun. How many times more bright is this star compared to our Sun? 9actionNow, take a look at the "Red Giants". Read through this section as you respond to the questions below. 10responseIn what part of a red giant star does hydrogen burning take place? 11responseIs the temperature of a red giant star greater or lesser than it was when the star was a main sequence star? 12responseHow much larger might a main sequence star like our Sun become when hydrogen burning in its core ceases? 13actionRead briefly through the "Supergiants and Supernovae" section. 14responseIn one sentence of your own words, sum up how heavier elements up to Iron are created within supergiants. 15responseThis section of the article refers to Nucleosynthesis. Take the word apart: What does Nucleo- refer to? 16response"Synthesis" refers to a "combination." Therefore, what does the process of nucleosynthesis in stars describe? 17responseComplete the sentence in your own words: A supernova is the result of a supergiant _______. 18actionRead briefly through the remainder of the article, covering White Dwarf stars, Neutron stars, and Black Holes. 19responseComplete the sentence in your own words: A White Dwarf star is a star that was once like our own Sun, but has _______. 20responseA Neutron star is what often remains after a supernova. If we had one teaspoonful of the neutron star's unique "neutron matter" here on Earth, about how many tons would it weigh? 21textThis article explains that a Black Hole is formed after a super-massive supergiant goes supernova (a lot of super-s), and the remaining neutron matter is packed into an extremely small volume for that amount of matter. The maximum distance radius required for a particular amount of mass to be compacted to form a Black Hole is called the Schwarzchild radius, and it depends mainly on just the mass of the object. You can calculate your own Schwarzchild radius; if all of your mass was packed into this radius, you would become a Black Hole. Calculate it!

Your Mass = [your weight in pounds] / 2.2

Waves are disturbances of energy that occur all around us, all of the time. Examples of waves include ripples in water, hand waves, and even sound and light. Let's find out what makes them tick.

https://surendranath.tripod.com/GPA/Waves/TW01/TW01.htmlhttps://surendranath.tripod.com/GPA/Waves/LW01/LW01.htmlTransverse WavesLongitudinal Waves

In the window to the right you should see a wave rippling. This type of wave is called a Transverse wave, because each of its segments MOVE VERTICALLY to the motion of the wave. Hence, the word Trans- (to move) Verse (vertically). As the wave progresses from left to right, each of the little beads moves up and down perpendicularly to the direction the wave travels. Follow the activity below, answer the questions, and then move on to Longitudinal Waves.

Longitudinal waves are also referred to as "compression" waves. Notice how the particles moving in the wave to the right COMPRESS together along the longitudinal axis of the wave. The particles being disturbed by a compression wave move parallel to the direction the wave is moving. Follow the activity below, answering all questions. Press the PRINT button when you complete all of the questions.0textRead the Transverse Waves introduction in the upper-lefthand corner of the screen.

Observe the transverse wave. Look closely at how the particles move up and down, yet the wave moves to the right.1actionDecrease the "Amplitude" to A, and then increase it to 3A. Observe what happens to the wave.2responseDescribe what a wave's amplitude is. Try to put your description in definition form.3actionIncrease the "Frequency" to high, and then back to low. Observe what happens to the wave.4responseAs frequency increases, what happens to the wave?5responseIs the wave moving faster, slower, or at the same speed? Defend your response. (Try counting how long it takes the top of the wave to travel from the left side to the right side)6actionChange the "Progressive Wave" selection box to "Pulsed Crest". Increase the frequency, observe the wave, and then decrease it again and observe.7responseDoes your response to the last question change? (In other words, does frequency affect the SPEED of the moving wave?)0textRead the Longitudinal Waves introduction in the upper-lefthand corner of the screen.

Waves are disturbances of energy that occur all around us, all of the time. Examples of waves include ripples in water, hand waves, and even sound and light. Let's find out what makes them tick.

https://www.surendranath.org/GPA/Waves/TW01/TW01.htmlhttps://www.surendranath.org/GPA/Waves/LW01/LW01.htmlTransverse WavesLongitudinal Waves

In the window to the right you should see a wave rippling. This type of wave is called a Transverse wave, because each of its segments MOVE VERTICALLY to the motion of the wave. Hence, the word Trans- (to move) Verse (vertically). As the wave progresses from left to right, each of the little beads moves up and down perpendicularly to the direction the wave travels. Follow the activity below, answer the questions, and then move on to Longitudinal Waves.

Observe the Longitudinal wave. Look closely at how the particles from side to side, and how the wave moves to the right.1actionPress the START BUTTON, and after a moment, press the STOP button. Observe the segments of the wave. Decrease the amplitude, then press the STOP button again.2responseHow is changing a Longitudinal Wave's amplitude similar to changing a Transverse wave's amplitude? How is it different?3actionNow, switch the amplitude back to "high" and then change the "frequency". Observe the waves in both high and low states. Observe what happens to the wave.4responseAs frequency increases, what happens to the wave's speed?5responseA guitar uses vibrating strings to produce sound, and sound is an example of a longitudinal wave. What do you think will happen to the pitch of a note played by a guitar if the string's frequency of vibration is increased? Explain.6actionChange the "Progressive Wave" selection box to "Pulsed Compression". Let a pulsed wave move to the center of the screen, and press the STOP button.7responseHow does this compression pulse wave compare to a transverse pulse wave? shully Moving Charges in E and B Fields AR2 3 300 Moving Charges in E and B Fields https://www.geogebra.org/material/iframe/id/449011/width/919/height/539/border/888888/rc/false/ai/false/sdz/false/smb/false/stb/false/stbh/true/ld/false/sri/true/at/auto https://www.geogebra.org/material/iframe/id/2369605/width/1174/height/662/border/888888/rc/false/ai/false/sdz/false/smb/false/stb/true/stbh/true/ld/false/sri/true/at/auto https://people.physics.carleton.ca/~robinson/EB%20field/EM.html Charge in a B-field Charge in a B-field (3D) Mass and Velocity Selectors 0actionHit the 'Start' button and observe the path of the charged particle. 1responseWhen the particle enters the magnetic field, does it accelerate by speeding up, slowing down, or changing direction? 2responseWhat single word describes the type of acceleration that the particle undergoes when it enters the magnetic field? 3responseReflect on each situation: If each of the following variables is increased, do you predict that the radius of charged particle's path will increase, decrease, or remain the same? 1) Mass, 2) Velocity, 3) Charge, 4) B-Field Strength? 4actionTest your predictions! First, initially set the Mass to 2, Velocity to 5, Charge to 2, and Magnetic Field Strength to 5. Clear the Trace and hit 'Start' to observe an initial motion. 5responseRecord the diameter of the particle's circular path: 6responseDouble the initial Mass to 4. Record the new diameter. (then reset the mass to 2) 7responseDouble the initial Velocity to 10. Record the new diameter. (then reset the velocity to 5) 8responseDouble the initial Charge to 4. Record the new diameter. (then reset the charge to 2) 9responseDouble the initial B-Field Strength to 10. Record the new diameter. (then reset the field strength to 5) 10actionLook back at our predictions and reflect: Did you predictions agree with the outcome? 11textIt all comes down to Newton's 2nd Law, F=ma, where F=qvB, 'm' is the mass of the particle, and 'a' is the centripetal acceleration where a_c=v²/r

On a sheet of paper, substitute those expressions into F=ma, and use algebra to solve for the radius 'r'. You should arrive at the same proportionality outcomes! 0textUse this animation to visualize how a charged particle's path would look as it moves through 3-dimensional space within a magnetic field. 1actionPlay around with the different settings, including the 'View from Above' vs. 'View in 3D' settings. Notice how changing the v₀z setting does not change the radius of the particle's circular motion, because that componenet of the velocity is in the same direction as the magnetic field. (There are no questions to respond to for this section) 0textVelocity Selector 1actionLook up (from this lesson's notes) how create a Velocity Selector using an Electric Field in tandem with a Magnetic Field. Determine the Electric Field strength that you would need for a charged particle moving at 5 m/s through a 1.6T Magnetic Field, in order for its path through the velocity selector to be perfectly straight. 2responseRecord your response for the Electric Field strength required in this velocity selector. 3actionInput an Initial Velocity of 5 m/s, Magnetic Field of 1.6T, and your determined Electric Field strength into the simulator, and press the 'Update" button. 4responseDoes the Velocity Selector work, producing a straight path? 5responseWhat do you think will happen if the mass or charge of the particle is changed? Will the velocity selector still work? Why or Why Not? 6actionTry it! Change the mass and the charge to different values. If the path remains constant, then the two fields will 'select' any and all charged particles, no matter their mass or charge value or polarity, by allowing them to pass through in a straight line. 7IMPORTANT!When you press the 'End Session and Print' button below, you will enter your name and it will produce a print-out. YOU MUST copy and paste this into a Google Doc and submit it to the Schoology assignment. DO NOT CLOSE THIS WINDOW/TAB until you have copied it onto the Google Doc, or you will lose all of your responses.