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 if there is no air resistance.
A) Cannot be determined without knowing the mass of both James and John.
B) James and John will reach the surface of the lake at the same time.
C) John reaches the surface of the lake first.
D) Cannot be determined without knowing the weight of both James and John.
E) James reaches the surface of the lake first.

Question

Quizplus · Accepted Answer

The time it takes for both James and John to reach the lake depends only on the vertical distance they fall, not on their horizontal velocities. Since there is no air resistance, their masses or weights do not affect the time of fall. Gravity acts equally on both, so they will reach the surface at the same time.

James and John Dive from an Overhang into the Lake