A man lifts a 20.0-kg bucket of concrete from the ground up to the top of a 30.0-m tall building. The bucket is initially at rest, but is traveling at 4.0 m/s when it reaches the top of the building. How much work was done by the man in lifting the bucket?
A)5.88 kJ
B)600 J
C)760 J
D)6.04 kJ
E)160 J

Question

Quizplus · Accepted Answer

The work done by the man includes both the gravitational potential energy gained by the bucket and the kinetic energy it has at the top. The potential energy is mgh = 20 kg * 9.8 m/s² * 30 m = 5880 J. The kinetic energy is 0.5 * 20 kg * (4 m/s)² = 160 J. Total work done = 5880 J + 160 J = 6040 J or 6.04 kJ.

A Man Lifts a 20