posted by Emily .
A 29.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 17.00 m. When she is partway down the slide, at a height h2 of 8.00 m, she is moving at a speed of 6.90 m/s. Calculate the mechanical energy lost due to friction
Between h1 and h2 she has lost this amount of PE=mg(h1-h2), which is the PE change.