FREE point (heres some random words cuz said my question was short lol)

Could someone me find the answer to this problem.

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?