10. A ball is thrown upward. At a height of 10 meters above the ground, the ball has a potential energy of 50 joules (with the potential energy equal to zero at ground level) and is moving upward with a kinetic energy of 50 joules. Air friction is negligible. The maximum height reached by the ball is most nearly
(A) 10 m
(B) 20 m
(C) 30 m
(D) 40 m
(E) 50 m
(A) 10 m
(B) 20 m
(C) 30 m
(D) 40 m
(E) 50 m