Question

1. A 40 kg crate is moving on a level surface. The kinetic frictional coefficient is 0.447. What horizontalforce is needed to cause the crate to accelerate at 4.1 m/s^2

2. A repressed factory worker pulls a box with mass 102 kg on a horizontal surface with a constant velocity of 3.5 m/s. The coefficient of kinetic friction between the box and the surface is 0.2. a) What force must he apply when he pulls up at an angle of 30 degrees with the horizontal? b) What force must he apply when he pulls horizontally on the box?

3. Draw a free body diagram for the problem given below. Ted pulls a penguin on a sled up a 17 degree hill, the penguin and sled have a combined weight of 1078 N. The force that Ted applies is applied at a 20 degree angle above the incline. The coefficient of friction between the sled and the hill is 0.45. How much force does Ted apply?

Answer 1