A stone is released from rest from the edge of a building roof 190 m above the ground.Neglecting air resistance, the speed of the stone, just before striking the ground, is:
A)43 m/s
B)61 m/s
C)120 m/s
D)190 m/s
E)1400 m/s

Question

Quizplus · Accepted Answer

The speed of the stone just before striking the ground can be found using the equation for the final velocity of an object in free fall: $v = \sqrt{2gh}$, where $g = 9.8 \, \text{m/s}^2$ is the acceleration due to gravity and $h = 190 \, \text{m}$ is the height from which the stone is dropped. Plugging in the values, we get $v = \sqrt{2 \times 9.8 \times 190} \approx 61 \, \text{m/s}$.

A Stone Is Released from Rest from the Edge of a Building