Just before striking the ground, a 2.0 kg mass has 400 J of KE. If friction can be ignored, from wha

Question

Just before striking the ground, a 2.0 kg mass has 400 J of KE. If friction can be ignored, from what height was it dropped?

Professor PC Thomas Classes · Answer

$mgh = KE \Rightarrow h = \frac{400}{2 	imes 9.8} \approx 20 	ext{ m}$.