# 13-15-19-21 (3 parts due 29) November Science 7 Summative Project Description

• a. Mindful moment.
• b. Review previous DSN entries about motion.
• c. Preview blogpost with Plan for today (and summative project description).
• d. Prepare DSN for today. Your entry will consist of the work done on poster, description, reflection.

• * * * *

### Be sure to use the important concepts we have studied this year with regard to motion:

• ##### Momentum and conservation of momentum

ALSO:

Write a thorough description of your investigation and a thorough explanation of your device and its motion to accompany the picture of your poster. In this description explain your poster.

Write a thorough and thoughtful reflection describing what you have learned about motion from working with and observing the comeback cans. Refer to your prior ideas and to the various experiences and experiments we have done this year. What surprised you about the comeback can? What has surprised you about the science of motion? What questions about motion, comeback cans, and other oscillating systems do you still have? Record the reflection in your DSN.

Turn in paper copies of your poster, your description, and your reflection. These should also be stored together in your DSN in a folder inside your motion folder. Due 27 November at the beginning of class.

Investigate the parameters of performance of your device.

Control the “launch.” (You need to start with untwisted rubber bands; then count the turns and use the same number of turns on each trial; OR use an inclined plane set at a constant angle and let the can roll down from the same spot.)

How do the number of turns affect the outgoing distance, the return distance, and the 2nd outgoing distance (and so on)?

If you use a set number of turns to start, what is the average speed of the outgoing trip? What is the average speed of the return trip? What happens if you change the number of turns for starting?

How are the number of oscillations of the device affected by the number of starting turns?

Video a motion event with a ruler in the background. Describe the acceleration on the outgoing trip and on the return trip.

How much force/torque is generated by your device? How steep an incline can it climb? Control the number of starting turns in the rubber band and measure the angle of inclination on an inclined board.

• * * * *

What is your explanation for the behavior of the device?

How could you test that explanation–that is, find support for it by predicting a consequence of your explanation being true, OR challenge the explanation by obtaining a result that contradicts what is predicted by your explanation? This/these test(s) would be a real experiment.

Remember to incorporate an understanding of the important concepts and quantities we have used to study motion:

• Distance
• Time
• Speed
• Velocity
• Inertia (Newton’s 1st Law)
• Acceleration
• Force (Newton’s 2nd Law) (now, Torque) (also friction)
• Contact and non-contact forces (gravity is a non-contact force)
• Equal and opposite forces (Newton’s 3rd Law)
• Momentum and conservation of momentum
• * * * *

Poster is due on 27 November

CONSTRUCTING, OPERATING, INVESTIGATING A MOTION DEVICE THAT EXHIBITS CHANGING VELOCITY (ESPECIALLY OSCILLATION)

The purpose of our second summative project on motion is to assess your skill and knowledge of motion and scientific practices. This project is based on your success at designing, building, investigating, and explaining a motion device that exhibits changing velocity. Our first project focused on constant velocity. This second project examines changing velocity, especially through the action of an oscillating device.

You may work in a group of 3, a group of 2, or individually. It will be difficult to conduct tests of performance individually.

Step 1: Make a plan with your group and with yourself on how you will operate as a group. Set up an organized system for recording your thoughts, procedures, and findings throughout the entire project / investigation. Use the recommendations for the steps of making a DSN entry–what do/did you do, what do/did you see, what do/did you talk about, what do/did you think–use sketches and photos extensively. Stick to your plan.

Step 2: Observe the action of the demonstrated device.

Step 3: Observe video clips 1 and 2 below.

Step 4: Discuss your observations with your team. Record them. Distinguish between what you see and what you think causes the action. (Distinguish between observation and inference). Be sure that this discussion is recorded in your notes.

Step 5: Make a sketch of how you think the device is constructed. Each member of the group should do this. Describe your proposed mechanism in words. Explain the action in terms of the various concepts of motion we have discussed. Each member of the group should do this.

Step 6: Build a device that is based on your design. Do not engage in any construction practices that are unsafe. You must consult me or a teaching assistant before cutting or making a hole in metals, plastics, or stiff cardboard. Keep track of each attempt. Keep track of your revisions and the effect these have on the performance of your device.

Step 7: Demonstrate your device. It must meet certain requirements (parameters of performance) before you proceed to the next step.

Step 7 a: If you get stuck, take a look at the video clip below. What must take place in your device for the object to slow down, stop, change directions, speed up, an so on? If you continue to be stumped, ask me to send you a couple of other video clips showing a device that is transparent.

Step 8. If you have succeeded in building a device that meets the performance requirements, begin the investigation of its performance. Identify parameters relevant to our study of motion (for example distance travelled for each oscillation, times for each oscillation, average speed for each oscillation, number of oscillations under consistent starting conditions, description of pattern of acceleration in each oscillation, etc.). How will you initiate motion in a fair and consistent way? How consistent is the performance of your device? Keep excellent and well-organized records.

Step 9: Once you have an understanding of the operation of your device, explain the mechanism. Use ideas about motion that we have studied. Develop a way of testing your explanation. Carry out the test. In other words, design and perform an experiment(s) to support or challenge your explanation. Keep complete, well-organized records. (Hint: You may want to build a device that is transparent so that you can see what is actually happening inside when the device moves / oscillates.)

Step 10: Due date to be determined soon. Design and produce a (physical) poster (using no words and no numerals) that shows:

1. What you consider to be a typical “launch” and oscillatory motion event of your device.
2. The results from your tests of the parameters of performance.
3. Your proposed mechanism and the results of testing your explanation of the mechanism and its consequent motion.
4. How Newton’s 3 Laws of Motion apply. Think carefully about when the speed/velocity is changing and when it is constant. Think about where forces appear in the motion and identify the paired 3rd law forces.
5. How the principle of the Conservation of Momentum applies.

Write a thorough description of your investigation and a thorough explanation of your device and its motion to accompany the picture of your poster. In this description explain your poster.

Write a reflection after the summary describing what you have learned about motion from working with and observing the comeback cans. What surprised you? What questions about motion, comeback cans, and other oscillating systems do you still have? Record the reflection in your DSN.

• Upload a photo or video from one of the motion events of your comeback can to your DSN.
• STANDARDS FROM POWERSCHOOL
• 7.SC.BTH.A.3 – Planning and carrying out investigations
• 7.SC.BTH.B.7 – 7. Stability and Change
• 7.SC.BTH.C.1 – PS2.A: Forces and Motion

As you work with your device, consider how the following apply:

• Distance
• Time
• Speed
• Velocity
• Inertia (Newton’s 1st Law)
• Acceleration
• Force (Newton’s 2nd Law)
• Contact and non-contact forces
• Equal and opposite forces (Newton’s 3rd Law)
• Momentum and conservation of momentum

https://www.scientificamerican.com/article/rolling-race/