If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest?

Options

A. 1cm
B. 2 cm
C. 3 cm
D. 4 cm

Answer

A

Explanation

For first condition
Initial velocity = u, Final velocity = u/2, s = 3 cm
From `v^(2)=u^(2)-2as rArr ((u)/(2))^(2)=u^(2)-2as rArr a = (3u^(2))/(8s)`
Second condition
Initial velocity = u/2, Final velocity = 0
From `v^(2)=u^(2)-2ax rArr 0 = (u^(2))/(4)-2ax`
`therefore = (u^(2))/(4xx2a)=(u^(2)xx8s)/(4xx2xx3u^(2))=s//3=1cm`.