A stone is released from the top of a tower of height 19.6m. Calculate its final velocity just before touching the ground.

Options

A. 29.6 m/s
B. 26.6 m/s
C. 15.6 m/s
D. 19.6 m/s

Answer

D

Explanation

Given : u = 0, v = ?
h = s = 19 . 6
`g = 9 . 8 m // s^(-2)` (falling down )
From , ` v^(2) - u^(2) = 2 g s `
`rArr v^(2) - (0) ^(2) = 2 xx 9 . 8 xx 19 . 6 rArr v^(2) = 19 . 6 xx 19 . 6`
`rArr v = 19.6 m// s `
The final velocity just before touching the ground is 19 . 6 m/s .