5. Potential energy = mass x gravity x height
Potential energy = 55 kg x 9.8 m/s^2 x 27 m = 14,469 J
Kinetic energy = 0.5 x mass x velocity^2
Kinetic energy = 0.5 x 55 kg x (8 m/s)^2 = 1,760 J
6. Potential energy = mass x gravity x height
196 J = 5 kg x 9.8 m/s^2 x height
Height = 196 J / (5 kg x 9.8 m/s^2) = 4 m
Therefore, the book is 4 meters from the floor.
If a neighbor pushes a lawnmower four times as far as you do but exerts only half the force, which one of you does more work and by how much? 4. A 0.075 kg ball in a kinetic sculpture moves at a constant speed along a motorized vertical conveyor belt. The ball rises 1.32 m above the ground. A constant frictional force of 0.35 N acts in the direction opposite the conveyor belt’s motion. What is the net work done on the ball?
2 j/0.18 x 9.8 m/s = 1.13
5. Calculate the potential energy of a rock with a mass of 55 kg while sitting on a cliff that is 27 m high. Calculate the kinetic energy if the rock rolls down the hill with a velocity of 8 m/s. 6. What distance is a book from the floor if the book contains 196 J of potential energy and has a mass of 5 kg?
1 answer