A pole-vaulter just clears the bar at 5.53 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3200 J. What is his weight?

Can someone explain to me how to do this problem ?

The sun generates both mechanical and electromagnetic waves. which statement about those wave is true?

Edward tolman explained the results of his study by theorizing that the rats were learning about the maze during every trial but they a. were agitated because other groups were getting reinforcement b. could not remember how to demonstrate it without reinforcement c. were not motivated to demonstrate it without reinforcement d. seemed to be too lazy to actually work without reinforcement