posted by aly .
The physics of a golf ball and kinetic energy.
When a 0.045 kg golf ball takes off after being hit, its speed is 41 m/s.
a) What is the kinetic energy of the ball after it has been hit?
b) How much work is done on the ball by the club?
c) Assume that the force of the club acts parallel to the motion of the ball and that the club is in contact with the ball for a distance of 0.010 m. Ignore the weight of the ball and determine the average force applied to the ball by the club?
d) In moving through the air, the golf ball slows down to a speed of 31 m/s. What work has the air done on the ball?
e) If the ball travelled through the air a distance of 84 m, what must be the average force of resistance caused by the air?
Ke = (1/2) m v^2 = (.045/2)(41)(41)
Work in = increse in energy = Ke = answer to a
F * d = work = same Ke
new Ke = (.045/2)(31)(31)
so answer = this - answer to a
which is negative, force opposite to motion
again work done = change of energy = F (84)