Student Exploration: Force and Fan Carts
Vocabulary: force, friction, position, speed
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
If you are pushing a shopping cart and you start pushing harder, what happens?
2.What happens to a shopping cart if you get it rolling and then release it?
In the Gizmo™, turn the fan Off. Click Play (). Did the cart move?
2.Click Reset ( ). Press the Low fan speed button to turn on the fan. Click Play. What happened?
3.A force is something that causes change in motion. What provided the force that made the cart speed up?
4.The speedometer shows the cart’s speed, or how fast it moves. A speed of 30 cm per second means the cart moves 30 cm every second. What was the final speed of the cart?
5.Friction is a force that works against motion as surfaces rub each other. Click Reset. Select the No Friction surface. Click Play. What was the final speed this time?
Question: How does force affect motion?
1.Run Gizmo: Press Play. What was the final speed of the cart?
2.Predict: Would the cart’s final speed be higher or lower if the fan were set to Medium instead of Low?
3. Experiment: Click Reset. Change Fan speed to Medium. Click Play. What was the cart’s final speed?
4. Draw conclusion: Did the cart speed up more quickly with the fan on Low or Medium?
5. Generalize: On Medium the fan provides more force than on Low. Make two rules by filling in the blanks below. (Put the same word in both blanks.)
6. Predict: Select the Data tab. Choose Bar graph or Line graph. This graph shows the speed of the cart over time. How would this graph be different if the fan were on High? Why?
7. Test: Check your prediction with the Gizmo. What do you observe?
8. Extend: Design an experiment to test the effect of force on a loaded cart. You can choose any surface and any object to load onto the cart. On the back of this sheet or an additional sheet, report your question, prediction, procedure, observations, and conclusion.
Question: Why do objects slow down when there is nothing pushing them?