In this figure, why is the kinetic energy gained by the falling ball equal to the change of potential energy? (Assuming no loss of energy due to friction.)
a. Energy conservation requires that the total energy remains constant. In this example, the total energy is either in the form of kinetic energy or potential energy.
b. This follows from momentum conservation.
c. Both a. and b.
d. Because the total energy decreases as the ball falls.
e. Because the total energy increases as the ball falls.
Question 2
As a falling object's gravitational potential energy decreases:
a. its kinetic energy decreases.
b. its kinetic energy increases.
c. its total mechanical energy increases.
d. its kinetic energy remains the same.
e. it falls more slowly.