Physics Practice: Circular Motion, Torque & Angular Momentum

These are the formulas you will use on the test.

What's the centripetal acceleration of a .2 kg yoyo spun in a circle with a radius of .7 meters at a velocity of 3 m/s?

• 8.23 m/s²

• 10.54 m/s²

• 12.86 m/s²

• 17.39 m/s²

Calculate the centripetal force required to make a 5 kg ball move 4 m/s in a circle with a radius of 2 m.

• 10 N

• 20 N

• 30 N

• 40 N

You are moving a ball in a circle using 72 N of centripetal force. What would the force be if you doubled the radius of the circle?

• 18 N

• 36 N

• 72 N

• 144 N

Bruno the bat flies at a speed of 0.5 m/s in circle of radius 1 m. What is his acceleration? (Hint: a_c = v²/r )

• 0.25 ms^-2

• 0.5 ms^-2

• 1 ms^-2

• 2 ms^-2

A vinyl record rotates through 20 rotations in 5 seconds. If the record starts from rest, what is the angular velocity?

• 5 rotations/s

• 100 rotations/s

• 4 rotations/s

• 10 rotations/s

The tangential speed at the outer rim of a carousel is 8.0 m/s. What is the tangential speed of a position halfway from the center to the outer rim?

• 8 m/s

• 4 m/s

• 16 m/s

• 2 m/s

Two children are sitting on a see-saw, as shown. Calculate the distance the 500-N child should sit from the fulcrum in the center (pivot) of the lever to balance the see-saw.

• 1.8 m

• 3m

• 5 m

• 1 m

If the torque required to loosen a nut on the wheel of a car has a magnitude of 60.0 N• m, what minimum perpendicular force must be exerted by a mechanic at the end of a 0.45 m wrench to loosen the nut?

• .666 Nm

• 133.3 N

• 66.7 N

• 13.3 Nm

If the torque required to loosen a nut on the wheel of a car has a magnitude of 60.0 N• m, for a 0.45 m wrench to loosen the nut, how much torque would be needed if a pipe extended the length of the wrench to 0.90 m?

• 60 Nm

• 30 Nm

• 120 Nm

• 54 Nm