Rockets WebQuest
This WebQuest will help students gain an understanding of rockets and rocket flight, how physics fundamentals are related to rockets, and how we will use model rockets.
(alternate site:http://exploration.grc.nasa.gov/education/rocket/bgmr.html )
After you read each page, click on the NEXT button.
Make sure you click on the NEXT button next to the topic you are on. For example, when in “Rocket Flight”, multiple sections appear at the bottom of the page. Make sure you click on the one next to “Rocket Flight”.
Take notes on each page you visit. Your notes will be graded as the first part of the Rockets Unit. Pay particular attention to the “Model Rocket” section of “Types of Rockets.”
Color Vision (or Seeing Colors)
Objective: Differentiate between color addition and color subtraction.
http://phet.colorado.edu/simulations/sims.php?sim=Color_Vision
Ever wonder how all the colors of the rainbow come from normal sunlight? After all, your elementary school art teacher told you that if you mix all of the colors of the rainbow you end up with a dark, muddy brown mess. Which is right? Which is wrong? Or are rainbows and paints following different rules?
General: Play with the simulation for a few minutes. (Not more than 5.)
1) What do you think the moving, colored dots represent?
2) What do you think the colored cloud above the man’s head represents?
Color addition:
3) What color does the man perceive when the red light is turned up to full intensity?
4) What color does the man perceive if the light is turned up to just ¼ of full intensity?
5) Form a hypothesis to explain these two results:
6) Attempt to confirm your idea. Explain how you attempted this:
7) Return the red to full intensity. Based on what you know from elementary school art, what color would you expect if you were to add green at full intensity?
8) What color is actually seen when green is added at full intensity?
9) Form a hypothesis to explain the results from the previous two questions:
10) What color is perceived when red and blue are viewed at full intensity?
11) What color is perceived when green and blue are viewed at full intensity?
12) Pause for a moment. Based on the results so far, what color would you expect when red, green, and blue are all viewed at the same time?
13) Now try the experiment at full intensity?
14) Do these last few experiments have more to do with rainbows or paints? Why?
Red, green, and blue are commonly referred to as the primary additive colors and are used in TV screens and computer monitors. Addition of varying amounts of these primary additive colors generate the enormous variety of colors that can be displayed. You can see these primary colors by placing small lenses on the screen.
15) Approximately how much of each color should be mixed to generate brown?
red ________ green ________ blue ________
16) Approximately how much of each color should be mixed to generate purple?
red ________ green ________ blue ________
17) Approximately how much of each color should be mixed to generate orange?
red ________ green ________ blue ________
18) What is different between these results and what you learned in art about color mixing?
In elementary school art you learned about mixing pigments. The primary subtractive colors are cyan, magenta, and yellow. These are exactly the colors you found by mixing any two primary additive colors at full intensity (Questions 8, 10, & 11). These colors still do not quite match your elementary school education; however, how many 1st graders know cyan and magenta? You are, nevertheless, quite familiar with these colors as they are used as pigments in every color ink jet printer to produce photo quality color images. Pigments produce colors by removing select wavelengths of light from the incident beam.
Color subtraction:
19) Select the single bulb tab from the top and change your beam from photons to a solid beam. What color is the incident light?
20) What color does the man perceive with a yellow filter?
21) Turn your beam into photons. Explain why the man perceives yellow using the words absorb and transmit.
22) Before making any further adjustments hypothesize what color the man will see using any color filter.
23) Test your hypothesis. Is it accurate? If not, revise.
24) Return your filter to yellow, make your beam solid, and select a monochromatic bulb type of yellow. What color does the man perceive?
25) Change your beam to photons and explain why this is the case.
26) Before making any more changes, hypothesize what might happen if the filter is changed to red.
27) Do the experiment. Is your hypothesis confirmed? If not, revise your hypothesis.
28) Return both your light and filter to yellow. Hypothesize what might happen if the light is changed to blue.
29) Do the experiment. Is your hypothesis confirmed? If not, revise your hypothesis.
30) Return both the light and filter to yellow. Hypothesize what might happen if the filter is changed to light orange.
31) Do the experiment. Is your hypothesis confirmed? If not, revise your hypothesis.
32) Generalize your hypothesis. In other words, what will happens when the filter and bulb colors are nearly the same? What will happen when the bulb colors are very different?
33) Play with the program to test your hypothesis. Revise if necessary.
34) After experimenting with the program, what insightful question would you have future students answer? (Be sure to provide your answer as well as the question!)
Geometric Optics Lab
1. Go to http://phet.colorado.edu/simulations/sims.php?sim=Geometric_Optics, where you will find the Geometric Optics activity. Click “RUN NOW”. Take the pencil and raise it so that the eraser is sitting on the principal axis. Click on the “principal rays” button.
(you will need Adobe Flash on your computer. You can get it here.
1.1 Draw the ray diagram. Describe the three special principal rays: how do they enter the lens, and how do they exit the lens?
1.2 There are several properties of the lens you can change in this simulation. For each one below, PREDICT what you think the effect will be on the image (its size, location, and brightness), then give the actual answer:
a) Radius of curvature of the lens
b) Refractive index
c) Diameter
1.3 You can change the location of your object (the pencil). Drag the pencil so that it is farther away from the lens. Explain the result.
1.4 Drag the pencil so the eraser is right on top of the focus. Draw the ray diagram.
A) What happens to the two principal rays that enter the lens? B) Will they ever form an image?
2. Get a magnifying lens and use it to look at this paper.
2.1 How do you use the lens to make the words appear larger? Find the spot where the magnification is highest and explain in terms of the focal length of the lens.
2.2 Sketch a ray diagram of how you think the magnifying lens might work.
2.3 Now back to the sim: drag the pencil so it is inside the focus. Draw the ray diagram.
A) Will the rays ever form an image, and if so, where? Click on “virtual image” to check your answer.
B) Imagine that you are looking through the lens from the righthand side. What would you see? Use your answer, and your drawing, to explain how a magnifying lens works.
Go to http://www.physicsclassroom.com/Class/waves/
Read through all the lessons on waves and turn in a two page summary.
Students who were absent on Tuesday:Read through the page, answer any questions that are in the "lecture" part and summarize the content. Turn in the answers and summary next class.ASSIGNMENTS CAN BE TURNED IN ON THIS SITE!If you would like, you can do your work in Word, or another text editor, and then cut and paste it into the comments section. Select "Name/URL" for posting the comment, and then enter the names of the people in your group. You do not have to enter anything where it says "URL". I will then review it and grade it online.
