Question

I'm stuck again..
By how much does the gravitational potential energy of a 67 kg pole vaulter change if his center of mass rises about 3.0 m during the jump?

Answer 1

PE is the energy due to a body's position.
It is given by the formul PE=mgh, where m is the mass in kg, g is gravity and h is gain/loss in height.
Replacing values, you get PE as 67*9.81*3=?Joules.