James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below.
A) James reaches the surface of the lake first.
B) John reaches the surface of the lake first.
C) James and John will reach the surface of the lake at the same time.
D) Cannot be determined without knowing the mass of both James and John.
E) Cannot be determined without knowing the weight of both James and John.

Question

Quizplus · Accepted Answer

The time it takes to reach the lake depends only on the vertical component of the initial velocity (since there is no air resistance). Both James and John have the same initial vertical velocity (zero), so they will both take the same amount of time to reach the surface of the lake. John's initial horizontal velocity has no effect on the time it takes for him to reach the surface of the lake.

James and John Dive from an Overhang into the Lake