Question

A bullet of mass m moving with velocity v strikes a suspended wooden block of mass M. If the block rises to height h, then the initial velocity v the bullet must have been 

Answer 1

SoLuTiOn :

Given:

✏ Initial velocity of bullet = v

✏ Mass of bullet = m

✏ Mass of wooden block = M

✏ Height gained by block = h

To Find:

✏ Initial velocity of bullet

Concept:

• Energy conservation

✏ Initial kinetic energy = final potential energy

Calculation:

• Energy conservation :

$\mapsto \sf \: \frac{1}{2} m {v}^{2} = (M + m)gh \\ \\ \mapsto \sf \: m {v}^{2} = 2(M + m)gh \\ \\ \mapsto \sf \: {v}^{2} = \frac{2(M + m)gh}{m} \\ \\ \mapsto \: \underline{ \boxed{ \bold{ \rm{ \purple{v = \sqrt{ \frac{2(M + m)gh}{m}}}}}} } \: \bigstar$

Answer 2

I HOPE THIS HELPS....