A ball falls from a height h from a tower. Which of the following statements is true?
(A) The potential energy of the ball is conserved as it falls.
(B) The kinetic energy of the ball is conserved as it falls.
(C) The difference between the potential energy and kinetic energy is a constant as the ball falls.
(D) The sum of the kinetic and potential energies of the ball is a constant.
(E) The velocity of the ball is constant as the ball falls.
Ans: (D) The sum of the kinetic and potential energies of the ball is a constant.
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