Question

A stone is released from the top of a building 78.4m high. Its final velocity just before touching the ground is

Answer 1

Explanation:

GIVEN :-

Distance , s = 78.4m

Initial velocity , u = 0

final velocity , v = ?

According to Newton's third law of motion

===> v² = u² + 2gs

===> v² = ( 0 ) ² + 2 × 9.8 × 78.4

===> v² = 0 + 1536.64

===> v = √1536.64

===> v = 39.2 m/s

Here , g = acceleration due to gravity which is equal to 9.8 m/s .

Hence , final velocity , v is 39.2 m/s .