Question

On the Apollo 14 mission to the moon, astronaut Alan Shepard hit a golf ball. The acceleration due to gravity on the moon is 1/6 of its value on the earth (gravity on moon -1.633m/s2). On earth, golf balls are driven at about 70 m/s with a loft angle of about 15º and have a range of about 200 meters. Given the same initial speed and loft angle as on the earth, what was (a) the time of flight for the golf ball and (b) how far did it travel horizontally on the moon?

Answer 1

Vo = 70m/s[15o]
Xo = 70*cos15 = 67.61 m/s.
Yo = 70*sin15 = 18.12 m/s.

a. Y = Yo + g*Tr = 0 @ max ht.
Tr=-Yo/g = -18.12/-1.63 = 11.12 s.=Rise
time.

Tf = Yr = 11.12 s. = Fall time.

Tr+Tf = 11.12 + 11.12 = 22.24 s. = Time in flight.

b. Range = Xo * (Tr+Tf) = 67.61 * 22.24 = 1504 m.

Answer 2

Correction: Change Tf = Yr to Tf = Tr.