1.

Two cubes hang from a meter stick. The meter stick is supported at its center and has a mass of 1kg. A 3kg cude is suspended by a string from the left end of the meter stick and a 4kg cube is suspended 20cm from the right end . Give the distance of the 3kg cube from center in order to balance the meter stick ?

2.

If you exert a perpendicular force of 15N 0.75m from the hinge of a door, calculate the torque on the door.

3.

If you exert a force of 5N on a door, and the torque of the door is 0.76 N·m, at what distance away from the hinge is the force exerted?

4.

A see-saw is supported at the center. A 40kg boy sits at the left, 4 m away from the center, and a girl sits 5 m at the right, 5 m away form the center. If the see-saw is balanced, what is the mass of the girl?

5.

If the girl in the above question is 25 kg, then how far away from the center does she have to sit if the see-saw has to be in equilibrium?

6.

If you hold a 5 kg ball in your hand, which is 30 cm away from your elbow, what is the torque on your forearm, assuming that the forearm is weightless, and the pivot is at the elbow?

7.

If a force of 60 N is applied to a door at an angle of 45 degrees, and it is applied at 30 cm away from the hindge, what is tht torque on the door?

8.

If a force is applied to a door at an angle of 45 degrees, and it is applied at 30 cm away from the hindge, find the magnitude of the force if the torque on the door is 15 N·m.

9.

If a torque of 0.06 N·m is needed to open a pop can, and an average person can exert a force of 4 N on the handle without breaking his fingernail, how long should the handle be made?

10.

If a 50 kg boy sits 3 m left of the center of the see-saw, and a 40kg girl sits 5 m right of the center of the see-saw, where should the see-saw be supported if the see-saw has a mass of 70kg and a length of 10 m?