A girl throws a stone from a bridge.Consider the following ways she might throw the stone.The speed of the stone as it leaves her hand is the same in each case,and air resistance is negligible. Case A: Thrown straight up.
Case B: Thrown straight down.
Case C: Thrown out at an angle of 45° above horizontal.
Case D: Thrown straight out horizontally.
In which case will the speed of the stone be greatest when it hits the water below?
A) Case A
B) Case B
C) Case C
D) Case D
E) The speed will be the same in all cases.

Question

Quizplus · Accepted Answer

In the absence of air resistance, all objects near the Earth's surface accelerate downwards at the same rate regardless of their initial motion. This means that the final speed of the stone when it hits the water depends only on the height from which it is dropped and not on the direction in which it is thrown. Therefore, the speed will be the same in all cases when the stone hits the water.

A Girl Throws a Stone from a Bridge