4. A ball fell to the floor after rolling off a table. What was true of the ball's energy as it fell? A. The ball's potential energy must have remained the same as it fell to conserve
mechanical energy.
B. The ball's kinetic energy must have remained the same as it fell to conserve mechanical
energy.
C. The ball's potential energy decreased as it fell, so its kinetic energy must have increased
to conserve mechanical energy.
D. The ball's potential energy decreased as it fell, so its kinetic energy must have decreased
to conserve mechanical energy.
5. A child picks a ball up from the ground, then places it on a table. The ball rolls on the table's
surface. Which statement is true?