Question

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?
[2002]
(a) 1 cm
(b) 2 cm
(c) 3 cm
(d) 4cm.​

Answer 1

Answer:

1 cm more

Explanation:

Initial velocity = x  

Final velocity = x / 2 after covering 3 cm distance

V2 – u2 = 2as

2as = x2/4 – x2

a = - x2/8

then final velocity is zero

 V2 – u2 = 2as

0 – x2/4 = 2(- x2/8) s

S = 1cm

sorry first attempt was not true.

Answer 2

Answer:

initial velocity :u

final velocity u/2

by applying v^2-u^2=2sa

a will be u^2/8

for next case initial velocity will be u/2

final velocity is 0

again by applying above eqn we get s=1 cm