1. If Galileo dropped a 2.50-kg cannon ball from the 58.4-m Tower of Pisa, how much work did gravity do on the ball?

2. You push a heavy box, applying a 540-N horizontal force in the direction of motion while the box slides 3.5 m across the floor. How much work do you do?

3. An object moves 2.50 m in the x -direction under the influence of a 125-N force 50°directed above the x-axis. Find the work done on the object.

4. A 1320-kg car moves in the x-direction with speed21.5 m/s Assuming constant braking and drag forces, find

(a) the force and

(b) the work needed to stop the car in a distance of 145 m.