You throw a softball (of mass 400g) straight up into the air. It reaches a maximum altitude of 15.2m and then returns to you.
What is the gravitational potential energy of the softball at its highest position? Assume the ball departed from and returned to ground level.
Assume no energy is lost by the softball while it is in the air.
What is the kinetic energy of the softball as soon as it leaves your hand?
What is the kinetic energy of the softball when it returns to your hand?
What is the speed of the ball?
PE = mgh
KE = (1/2)mv^2
The Attempt at a Solution
I've already calculated the PE to be 59.584 J. I'm not sure how to calculate KE without a velocity.