A47.0-g golf ball is driven from the tee with an initial speed of 54.0 m/s and rises to a height of 24.6 m. (a) neglect air resistance and determine the kinetic energy of the ball at its highest point.

We can solve the problem by using the law of conservation of energy.

At the starting point, the ball has only kinetic energy, since its height is zero, so:


At its highest point, the ball has both potential energy and kinetic energy:

we can find the potential energy of the ball at its highest point:


For the law of conservation of energy, the initial mechanical energy should be equal to the final mechanical energy:

which becomes

that we can solve to find the kinetic energy of the ball at its highest point: