Agirl and her dog are running. the dog has a mass of 20kg. the girl has a mass of 60 kg. suppose both the dog and the girl run at a speed of 2 m/sec. calculate both of their kinetic energies. show your work.

suppose the dog speeds up and is now running at a speed of 4 m/sec. calculate the dog's kinetic energy. show your work.

When you jump from an elevated position you usually bend your knees upon reaching the ground. by doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. in this way the average force your body experiences is a) less than 1/10 as great. b) more than 1/10 as great. c) about 1/10 as great.d) about 10 times as great.