Alice and Bill are at the top of a cliff of height H. Both throw a ball with initial speed v0,
Alice straight down and Bill straight up. The speeds of the balls when they hit the ground
are vA and vB. If there is no air resistance, which is true?
(A) vA < vB (B) it depends on how hard the ‘downwards’ ball was thrown.
(C) vA = vB (D) vA > vB
