Relative speed of falling objects · PhysicsBowl 2013 #33

Physics · mechanics

Problem

At the top of a high cliff, a small rock is dropped from rest. A ball is launched straight downward with an initial speed of

v_0

at a time

t_0

after the rock was dropped. When the ball has fallen

h

further than the initially dropped rock, what is the speed of the ball relative to the rock? (A)

v_0

(B)

2v_0

(C)

\sqrt{2gh + v_0^2}

(D)

\sqrt{2gh}

(E)

gt_0