Question

A bullet strikes a uniform plank with a velocity of 400 m/s and comes out with half velocity.
What would be the velocity if the plank were only half thick?

Answer 1

thickness=s

acceleration of the bullet inside plank=-a

200^2-400^2=-2as

as=60000 units

v^2-400^2=2*a*s/2

v^2=160000-60000

=100000 units

v=100√10 m/s