A bullet moving with a speed of `150ms^-1` strikes a tree and penetrates 3.5 cm before stopping. What is the magnitude of its retardation in the tree and the time taken for it to shop after striking the tree?

Explanation

u=150 m/s,s=3.5 cm=0.035 m,v=0 ,`v^(2)-u^(2)`=2as
`0-150^(2)=2xxaxx0.035`
`a=(-150xx150)/(2xx0.035)=-3.214xx10^(5)m^(-2)`
Time `=(v-u)/(a)=(0-150)/(3.24xx10^(5))=(-150)/(3.24xx10^(5))=4.67xx10^(-4)`sec