A diver springs upward with an initial speed of 2.1 m/s from a 4.5 m board.

Question

(a) Find the velocity with which he strikes the water. (Hint: When the diver reaches the water, his displacement is y = -4.5 m (measured from the board), assuming that the downward direction is chosen as the negative direction.)b. What is the highest point he reaches above the water?

Answer 1

(a) His kinetic energy will increase by M g H, where H = 4.5 m. Therefore
V2^2 = V1^2 + 2 g H
V1 = 2.1 m/s

(b) The increase in height at the highest point, h, is the elevation at which the potential energy increases by (1/2)MV1^2

2 g h = V1^2