Name___________________________
Period__________ Date____________
Lab # 11 Friction Computer Simulation
Running the simulation:
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Google search: PHET Forces and motion
basics
Click run now and keep
Click on the Acceleration tab;
In the upper right hand corner click all of the
boxes to provide feedback.
Directions:
1. Drag a crate to the sliding surface and gradually increase the force applied.
2. Initially what type of friction is present?______________
3. What happens to the force of friction when you gradually increase the applied force?
4. What is the maximum force of Friction?_______________
5. Push the crate until it is moving fast. Then stop pushing:
a. Does friction turn off? (describe the motion)
Direction of acceleration____
Direction of velocity ______
b. Does the amount of friction change as the crate changes speed?
5. Constant Velocity:
a. There are 2 two ways to get the crate to move at constant speed indefinitely. One
method is to adjust friction. Experiment, then describe how to get constant velocity
by varying friction.
Name___________________________
Period__________ Date____________
b. What part of the friction formula are you changing? __________
c. You can also get constant velocity while applying a constant force. What force
needs to be applied? _____________ (hint use the pause and play buttons to get
the crate moving at constant speed with an applied force.)
d. What happens to the velocity if you decrease the applied force?
6. Does the magnitude of kinetic friction depend on the velocity of the crate? State
evidence from your observations to support your statement.
7. Does the direction of kinetic friction depend on the velocity of the crate? Support your
statement.
6. Try to see if it is possible to have motion to the rightward (+) velocity and leftward (-)
acceleration? How did you achieve this?
8. Get a situation where velocity is to the right and the applied force and friction is
toward the left. How did you achieve this?
Does this system remain like this?
8. Is it possible to get friction in the same direction as the velocity? If not explain.
Name___________________________
Period__________ Date____________