Question

A bullet of mass 10 g moving with a velocity `300 ms^(-1)` strikes a wooden block and comes out from ot her side with a velocity of `200ms^(-1).` Find the work done by t he resistive force on the bullet.

Answer 1

`DeltaK=K_(f)-K_(i)=W`
`W=1/2mv ^(2)mu^(2).m=10xx10^(-3)kg,u=300m//sv=200m//s`
`W=K_(f)-K_(f)=1/2mv^(2)-1/2mu^(2)=1/2xx10xx10^(-3)xx(200^(2)-300^(2))`
`=-5xx10^(-3)xx500x100=-250J`