Over much deliberation, I agree with Pieter's answer. Perhaps I shall elaborate more. The equation of kinetic energy is $\frac{1}{2}mv^2$. The motion of the ball is a projectile motion, and can be resolved by 2 vectors: the horizontal and the vertical.

The vertical component of this velocity decreases by $-g$ as it approaches the maximum height. Hence, it's velocity at the maximum height is zero, as the energy over here has become potential energy.

The horizontal component, as a realised, remains constant, having no change in velocity(not no velocity!).

Hence, our resultant velocity is not zero. Hence $\frac{1}{2}mv^2$ is definitely not zero. Hence, only E, when the ball is at rest, is correct.

Over much deliberation, I agree with Pieter's answer. Perhaps I shall elaborate more. The equation of kinetic energy is $\frac{1}{2}mv^2$. The motion of the ball is a projectile motion, and can be resolved by 2 vectors: the horizontal and the vertical.

The vertical component of this velocity decreases by $-g$ as it approaches the maximum height. Hence, it's velocity at the maximum height is zero, as the energy over here has become potential energy.

The horizontal component, on the other hand, is not zero, and keeps on decreasing, as energy is lost via heat energy.

Hence, our resultant velocity is not zero. Hence $\frac{1}{2}mv^2$ is definitely not zero. Hence, only E, when the ball is at rest, is correct.

Over much deliberation, I agree with Pieter's answer. Perhaps I shall elaborate more. The equation of kinetic energy is $\frac{1}{2}mv^2$. The motion of the ball is a projectile motion, and can be resolved by 2 vectors: the horizontal and the vertical.

The vertical component of this velocity decreases by $-g$ as it approaches the maximum height. Hence, it's velocity at the maximum height is zero, as the energy over here has become potential energy.

The horizontal component, as a realised, remains constant, having no change in velocity(not no velocity!).

Hence, our resultant velocity is not zero. Hence $\frac{1}{2}mv^2$ is definitely not zero.

Over much deliberation, I agree with Pieter's answer. Perhaps I shall elaborate more. The equation of kinetic energy is $\frac{1}{2}mv^2$. The motion of the ball is a projectile motion, and can be resolved by 2 vectors: the horizontal and the vertical.

The vertical component of this velocity decreases by $-g$ as it approaches the maximum height. Hence, it's velocity at the maximum height is zero, as the energy over here has become potential energy.

The horizontal component, as a realised, remains constant, having no change in velocity(not no velocity!).

Hence, our resultant velocity is not zero. Hence $\frac{1}{2}mv^2$ is definitely not zero. Hence, only E, when the ball is at rest, is correct.