A bullet of mass `10^-3kg` strikes an obstacle and moves at `60^@` to its original direction. If its speed also changes from `20m//s` to `10m//s`. Find the magnitude of impulse acting on the bullet.

Answer

A, B, C

Explanation

Mass of the bullet `m=10^-3kg`

Consider components parallel to `J_1`.
`J_1=10^-3[-10cos 60^@-(-20)]` or `J_1=15xx10^-3N-s`
Similarly, parallel to `J_2`, we have
`J_2=10^-3[10sin60^@-0]=5sqrt3xx10^-3N-s`
The magnitude of resultant impulse is given by
`J=sqrt(J_1^2+J_2^2)=10^-3sqrt((15)^2+(5sqrt3)^2)` or `J=sqrt3xx10^-2N-s`