Question 14 A ball is thrown upward. At a height of10 meters above the ground, the ball has a potential energy of 50joules (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.10m b. 20m c. 30m d.40m e. 50m Question 15 Please read carefully, you must pick TWO of the answer choices!!! A block on a horizontal frictionless plane is attached to a spring, as shown above. The block oscillates along the xaxis with simple harmonic motion with a maximum displacement from the starting point of magnitude A. Which of the following statements about energy is correct? Choose TWO! A a. The kinetic energy of the block is at a maximum at x = A b. The potential energy of the spring is at a minimum at x = U. c. The kinetic energy ofthe block is at a minimum at x = A d. The potential energy of the spring is at a minimum at x = A. e. The kinetic energy of the block is always equal to the potential energy of the spring