# AP Physics B Problem Set I.E – Torque F2 F1 1. What is the 4. 3.

### AP Physics B Problem Set I.E – Torque

1. What is the minimum force required to open a door when the torque is 3.1 N∙m and the force is applied at 0.94 m from the hinges at an angle of 90.0° to the face of the door? (Ans. 3.3 N)

F 2 F 1

50.0° 90.0° 2. Two helmsmen, in disagreement about which way to turn a ship, exert forces shown below on a ship’s wheel. The wheel has a radius of 0.74 m and the two forces have magnitudes F 1 = 72 N and F

2

= 58 N. Find the magnitude and direction of the net torque on the wheel from the two forces. (Ans. 2 N∙m, cw) 3L/4 L/4

F 1 mg F 2

Mass m is supported on a light plank by two forces F

1

and F

2

as shown above. In terms of the given variables, find expressions for each of the forces that keep the plank in static equilibrium.

L

oval-shaped diver

d

A 5.00 m long diving board of negligible mass is supported by two pillars which are 1.50 m apart. Find the force exerted by each pillar when a 90.0 kg diver stands at the end of the board. Caution: what is the direction of the force exerted on the diving board by the pillar on the left? (Ans. F R = 2940 N, F

L