Problem: You are sitting on a deck of your house surrounded by oak trees. You hear the sound of an acorn hitting the deck. You wonder if an acorn will do much damage if instead of the deck it hits your head. Let the mass of the acorn be 3.5g. Suppose it drops from a height of 13m (relative to your head). Assume that the acorn sinks in 0.50 cm of your head skin before coming to a stop.
Part A: Determine the magnitude of the force that the acorn would exert on the head.
Can someone please explain what the heck is going on?