Making A Low Friction Balloon Air PuckS-5 Created for OP 3 October 2K+3
FORCES & MOTIONIVA1ROLLING ON AN INCLINED PLANE Created for OP 26 April 2K+2
Materials: • Inclined plane • Free‑wheeling toy car • Masking tape or chalk or movable place‑markers • meter stick • stop watch
1. Adjust the inclined plane so it takes the car at least three seconds to reach the bottom. Try for four or five seconds.
2. A timekeeper will call out seconds. Release the car at the top of the incline at one of the seconds.
3. Every time the timekeeper calls out another second, mark the incline to show where the car was at that second.
Measure the distance between the marks to find out how far the ball rolled during each second. • Record your measurements in the data table below.
Distance (in cm) Car Traveled During One Second • Trial 1st 2nd 3rd 4th 5th • 1 • 2 • 3 • Ave
5. Calculate the average velocity for each of the time intervals. Use the average distance from above. (The elapsed time is always one second.)
Table of Results • TimeIntervalAverage Velocity • (sec) (cm/sec) • 1st • 2nd • 3rd • 4th • 5th
6. What happened to the average velocity of the car as it rolled down the incline?
7. How much did the average velocity change between the first and second time interval?
8. How much did the average velocity change between the second and third time interval?
9. How much did the average velocity change between the third and fourth time interval (if you got this data)?
10. How much did the average velocity change between the fourth and fifth time interval (if you got this data)?
11. Did the average velocity change by about the same amount with every passing second? • Give the value.
12. Your answer to number 11 is called the rate of change of velocity. • It is the change in velocity divided by the elapsed time.
Its units are the units of velocity divided by the unit of Time • (usually meters per second divided by seconds or centimeters per second divided by seconds; • we would say "meters per second per second").
The rate of change of velocity is called the acceleration. Use your answer to number 11 and write out, with units, the average acceleration of the car as it rolled down the incline.
13. When you set up the inclined plane, what do you think the acceleration of the car would have been if the end of the incline had been lifted twice as high?
14. If the end of the incline had been lifted twice as high, what would you predict for the average speed during each of the time intervals?
15. Repeat the experiment using twice the height for the elevated end of the incline.
16. Discuss how well your new data matched your predictions. Include comments about the efforts of some other teams.
17. For your first set of data, if the car could continue accelerating on the same incline for 10 seconds, what would you predict for its average velocity during the tenth second?
The acceleration of gravity on Earth is 9.8 meters per second per second. If a rock is dropped from a sufficient height, how fast will it be going after: • 1 sec___ 2 sec___ 3 sec___
Force and Motion4A3Classifying Motionp 69 Created for OP 26 April 2K+2
Predict • Accelerated or not? • Not moving? • Speeding Up? • Constant speed, st. line? • Slowing down? • Changing Direction?
Cart and Accelerometer • At Rest • Long Slow Push • Constant Speed • Slowing down
Repeat – Be More Aggressive • Cart and Accelerometer • At Rest • Long Slow Push • Constant Speed • Slowing down
Repeat – Be More Aggressive • What does the “trusty” accelerometer demonstrate? • How does it display the direction of acceleration?
Cart on Incline • Going down the incline • Going up the incline • Going Up and Down incline
Cart on Incline • What is the direction of the acceleration of a cart on a ramp? • a. Going down? • b. Going up? • c. At the top?
What is the “trusty” accelerometer telling us? • a. To right, speeding up • b. To right, slow down • c. To right, constant speed • d. The repeat, to left? • e. At the top of ramp?
Cart on Incline • 15.
Cart on Incline • 16.
Cart on Incline • 17.
Force and Motion4B1Acceleration InCircular Motion72 Created for OP 26 April 2K+2
2. Rotate on stool with “trusty” indicator parallel to arm with arm outstretched.
3. Rotate on stool with “trusty” indicator parallel to arm but close to body.
4. When an object is moving in a circle at constant speed, what is the direction of acceleration?
Does the acceleration depend on how far from the center it is measured? • Demo: Multi-Accelerometer
6. What does “trusty” accelerometer say when it is placed on top of ones head.
Force and Motion4B2Acceleration When Speed and Direction Change75 Created for OP 26 April 2K+2