Practice solving high school physics problems involving angular displacement, angular velocity, torque, rotational inertia, angular acceleration, and rotational equilibrium.
Read each problem carefully. Show your work, include units, and state your final answer clearly.
Angular motion, torque, rotational inertia, and equilibrium
Physics - Grade 9-12
- 1
A bicycle wheel rotates through an angular displacement of 18 radians in 3.0 seconds. Calculate the average angular velocity of the wheel.
- 2
A disk starts from rest and reaches an angular velocity of 12 radians per second in 4.0 seconds. Find its average angular acceleration.
- 3
A student pushes perpendicular to a door with a force of 25 newtons at a distance of 0.80 meters from the hinge. Calculate the torque about the hinge.
- 4
A wrench is 0.30 meters long. A mechanic applies a force of 40 newtons at a 90 degree angle to the wrench. Calculate the torque produced.
- 5
A 15 newton force is applied to a 0.50 meter wrench at an angle of 30 degrees to the wrench. Calculate the torque. Use sin 30 degrees = 0.50.
- 6
A solid disk has a rotational inertia of 2.0 kilogram square meters. A net torque of 10 newton-meters acts on it. Calculate its angular acceleration.
- 7
A rotating object has a rotational inertia of 0.75 kilogram square meters and an angular velocity of 8.0 radians per second. Calculate its rotational kinetic energy.
- 8
A merry-go-round rotates at 2.0 radians per second. A child sits 1.5 meters from the center. Calculate the child's tangential speed.
- 9
A point on a spinning wheel has a tangential speed of 6.0 meters per second. The point is 0.40 meters from the center. Calculate the angular velocity of the wheel.
- 10
A 2.0 meter long uniform board is supported at its center. A 30 newton weight hangs 0.60 meters to the left of the center. How far to the right of the center must a 20 newton weight be placed to balance the board?
- 11
A figure skater spins with arms extended and then pulls the arms inward. Explain what happens to the skater's angular velocity and why, assuming no external torque acts.
- 12
A wheel completes 10 full rotations in 5.0 seconds. Calculate its average angular velocity in radians per second. Use 1 rotation = 2 pi radians and pi = 3.14.