As a 1.0-kg ball falls to the ground, its potential and kinetic energies are the same when the ball is 3.0 m above the ground. How fast is the ball moving just before the impact with the ground? A) 0 m/s B) 7.7 m/s C) 11 m/s D) 59 m/s E) 1.2 * 10² m/s

Question

Quizplus · Accepted Answer

The potential energy at 3.0 m is equal to the kinetic energy at that point. Using energy conservation, the total energy at 3.0 m is mgh = 1.0 kg * 9.8 m/s² * 3.0 m = 29.4 J. Just before impact, all this energy is kinetic: 0.5 * 1.0 kg * v² = 29.4 J. Solving for v gives v = √(2 * 29.4) = 11 m/s.

As a 10-Kg Ball Falls to the Ground, Its Potential and Kinetic