A bullet of mass `20g` enters into a fixed wooden block with a speed of `40 ms^(-1)` and stops in it .Find the change in internal energy during the process

Answer

A

Explanation

Since the bullet enters and stops insides the block , the total K.E.change by the bolled is responsible for the internal changes of the block
Change in internal energy
K.E. of bollet
`= (1)/(2) xx (20)/(1000) xx 40 xx 40 = 16J`