how to calculate the kinetic energy?
The goblins fists cut through the air and connects with the dwarfs face in an elastic collision. The goblins fists each weigh 2kg and the dwarfs head weighs 5kg. What is the kinetic energy imparted to the dwarfs face by the goblins fists if the goblins fists had an initial velocity of 5m/s? what equation(s) would I use to derive the answer? please let me know how to get the proper solution, thank you.