Question

A steel sphere is dropped vertically onto a horizontal metal plate. The sphere hits the plate with a speed u, leaves it at speed v, and rebounds vertically to half its original height. Which expression gives the value of v/u?

Answer 1

a) \[1/\sqrt{2}
b) 1-1/\sqrt{2}\]
c) 1/2^2
d) 1/2

Answer 2

compare KE and PE from stage1
to KE and PE of stage 2
\[
\frac{{1\over2}mu^2}{{1\over2}mv^2}=\frac{mgh}{mg{h\over2}}
\]

Answer 3

Okay, so it v/u is 1/sqrt{2}?

Answer 4

s