A penny has a mass of about 10 g. The penny falls from a height of 169 meter and, unfortunately lands right on the head of a man standing directly below it.
A) Ignoring air resistance, find the speed of the penny the instant it strikes the man's head?
B) The penny comes to rest on the man's head after penetrating the scalp a distance of 4.17 millimeter. Find the average force exerted by the penny on the head.