Question

The height of the empire state building is 318 m if a stone is dropped from the top of the building what is the stones velocity just before it strikes the ground

Answer 1

79 m/s. A stone dropped from the top of the Empire State Building will have a velocity of 79 m/s just before it strikes the ground.

This problem is about free fall, to find the velocity of the stone before it strikes the ground we have to use the equation
`v_(f)^(2)=v_(0)^(2)+2gh`, the initial velocity of the stone is 0 m/s. Then:

`v_(f)^(2)=2gh`

`v_(f)=√( 2gh)`

Solving the equation above with g = 9.8 m/s², and h = 318.0 m:

`v_(f)=\sqrt{ 2(9.8m/s^(2))(318.0m)}= 78.95 m/s`

`v_(f)`≅ 79 m/s