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.-035m, v=0`
`v^(2)-u^(2)=2as`
`0-150^(2)=2 times a times 0.035`
`a=abs((-150 times 150)/(2 times 0.035))`
`" "=-3.214 times 10^(5)m//s^(2)=-3.214 times 10^(5)m//s^(2)`
Time `=(v-u)/a=(0-150)/(3.214 times 10^(5))=(-150)/(3.214 times 10^(5))`
`" "=4.67 times 10^(-4)` sec.