math (calculate speed)
posted by AMT .
A swimmer of mass m is at a swimming pool. They climb the steps to the diving board 4.0 m above the water. They jump off the board, which enables them to rise a further 0.7 m before they begin their descent into the pool. At what speed do they enter the water?
You may assume that the acceleration due to gravity, g, is 9.8 m s−2
Show your working step by step, including the correct formulas and equations.

4.7 = 4.9t^2
t = .979 sec
v = 9.8t = 9.8*.979 = 9.6 m/s