A projectile of mass (m) is thrown with velocity (u) from the ground at an angle of ` 60^(@)` with the horizontal. What is the magnitude of change in momentum between leaving and arriving back at the ground ?

Explanation

In angular projection of a projectile, the horizontal copmonent velocity ` u cos theta` remains constant at all instants of its motion whereas projection so ` v cos theta` and at the point of return is `-v sin theta`. Thereform, magnituded of change in momentum`
`= mv sin theta + mv sin theta =2 mv sin theta`
` =2mv sin 60^(@) =2 mv xx sqrt 3 //2 =sqrt 3 mv`
acting in vertical direction.