A 1.00-kg ball has zero potential and kinetic energy.Maria drops the ball into a 10.00-m-deep well.After the ball comes to a stop in the mud,the sum of its potential and kinetic energy is:

Question

Quizplus · Accepted Answer

When the ball is at the top of the well, it has no kinetic energy and no potential energy. As it falls, it gains potential energy and loses an equal amount of kinetic energy at every point. When the ball comes to a stop in the mud at the bottom of the well, it has lost all of its kinetic energy and gained potential energy equal to the work done by gravity in pulling it down into the well. The potential energy gained by the ball is mgh=(1.00 kg)(9.81 m/s^2)(10.00 m)=98.1 J. The negative sign in the answer (C) indicates that the potential energy gained by the ball is negative with respect to the zero potential energy at the top of the well. The sum of potential and kinetic energy is therefore -98.1 J.

A 100-Kg Ball Has Zero Potential and Kinetic Energy