1) A box, originally at rest, slides down from point S to point T.

Assuming that the slope is frictionless, at which point does the box have about 25 % of its maximum kinetic energy?

2) A 4.0 kg mass is tied to a 10.0 kg mass and placed on a slope as shown in the diagram below. They are initially held at rest. The frictional force between the 4.0 kg mass and the plane of the slope is 4.0 N. When they are released, what is the kinetic energy gained by the system if the distance moved by the 10.0 kg mass is 2.0 m?

3) A crane lifts a load of 1000 N through a vertical height of 3.0 m in 10 s. The input power to the crane is 500 W. What is the efficiency of the crane?

4) A box of mass 6 kg is pushed horizontally by a 10 N force a distance of 6 m.

What is the work done on the box against the weight of the box?
(g = 10 m/s²)

5) A box, originally at rest, slides down a smooth slope from S to T.

At which point does the box have approximately 50 % of its final velocity?