PLS HELP :two forces 100N and 60N was initially at rest travelled with an acceleration of 5ms by -2, what was it's kinetic energy after 4 seconds

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 ?

What is the rate of change in a objects position?

While the change in blank will remain the same during a collision, the force needed to bring an object to a stop can be blank if the time if collision is blank