Lab #4: Forces and Motion Objective: Study the motion of an object on an incline and under force of friction Study the difference between kinetic and static friction Determine the relationship between the mass of an object and how far it slides Procedure: For this experiment you will be using Phet simulation Ramp: Forces and Motion

Lab #4: Forces and Motion

Objective:

• Study the motion of an object on an incline and under force of friction
• Study the difference between kinetic and static friction
• Determine the relationship between the mass of an object and how far it slides

Procedure:

For this experiment you will be using Phet simulation Ramp: Forces and Motion. The link to the simulation is https://phet.colorado.edu/en/simulation/legacy/ramp-forces-and-motion

Part 1: Free body Diagram on Ramp

1. Choose the introduction tab and select to show free body diagram.
2. Select wood, force vector, and brick wall.  On bottom choose crate.
3. Study the free body diagram of person pushing the crate up the ramp. Do this with wood and with ice.
4. For what value of the force will the crate start moving? To continue moving, do you increase or decrease the applied force.

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5. What direction is the force of friction vector pointing?

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Part 2: Friction  

1. Choose the friction tab and place the object at the top of the ramp.
2. At what displacement does the crate comes to rest?

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3. For different values of masses, find the minimum value of static friction for which the object does not slides down the incline.

Mass (kg)	μs
10	Click or tap here to enter text.
50	Click or tap here to enter text.
100	Click or tap here to enter text.
200	Click or tap here to enter text.

4. Does the coefficient of static friction depend on the mass?

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5. Set the mass to 100 kg. For different values of angle find the maximum coefficient of static friction

Angle θ (°)	μs
10	Click or tap here to enter text.
30	Click or tap here to enter text.
50	Click or tap here to enter text.

6. How does coefficient of static friction depend on the angle? What the mathematical relationship between them (check lecture notes)?

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7. Compare your data with the theoretical value. State the general trend.

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