A 30.0 kg child slides down a long slide in a playground. She starts from rest a
ID: 1983376 • Letter: A
Question
A 30.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 20.00 m. When she is partway down the slide, at a height h2 of 10.00 m, she is moving at a speed of 9.10 m/s. Calculate the mechanical energy lost due to friction (as heat, etc.).
Explanation / Answer
we have from work energy theorem, 0.5mv^2 - 0 = mgH - Wf 0.5 x 30 x 9.1^2 - 0 = 30 x 9.8 x 10 - Wf Energy lost= Wf = 1697.85 Joules