A projectile of mass `m` is fired with a velocity `v` from point P at an angle `45^@`. Neglecting air resistance, the magnitude of the change in momentum leaving the point P and arriving at Q is

Options

A. zero
B. `mv/sqrt(2)`
C. `mvsqrt(2)`
D. 2mv

Answer

C

Explanation

`Deltap = p_(f)-p_(i) = m(v_(f)-v_(i)`
`=m[(v/sqrt(2))hat(i) - (v/sqrt(2))hat(j))-(v/sqrt(2))hat(i)+(v/sqrt(2))hat(j))]`
`-sqrt(2)mvhat(j)`
`therfore |Deltap| = sqrt(2)mv`