A 47.0 g golf ball is driven from the tee with an initial speed of 54.0 m/s and rises to a height of 23.8 m.

(a) Neglect air resistance and determine the kinetic energy of the ball at its highest point.
J
(b) What is its speed when it is 10.0 m below its highest point?
m/s

2 answers

(a) Subtract the potential energy at 23.8 m from the initial kinetic energy.

(KE at highest pt.)
= (initial KE) - M g H

= (0.047 kg)*(54.0 m/s)^2/2
- (0.047)(9.8)(23.80 =

(b) 10.0 m below highest point is 13.8 m above tee elevation. Initial KE is decreased by M*g*13.8 m = 6.4 Joules at that elevation. Use that KE to get the corresponding speed
This formula is not very clear to me