Hello so my question is an 85kg kangaroo acquires 2.2kJ of energy in jumping straight up and down from rest. How high does the kangaroo jump?

My solution:

When he's at rest Eg=2200J but in air Eg=0

Eg=mhh
2200=85(9.8)h
2.64m=h

Looking at it now it doesn't really make sense that the eg would be 0 in the air. But I'm not really sure how to solve it. Thank you

"acquires" is an interesting term

the muscle energy on the ground (like a spring), becomes gravitational potential energy during the jump

it appears you have correctly calculated the height