Question

A projectile of mass 50 kg is projected vertically upward with a velocity of 100 m/s. After 5 seconds it explodes into two pieces, one piece of 20 kg moving vertically upward with a velocity of 150 m/s. The algebraic sum of the momentum of the system 3 seconds later is

• A. $2412kgm{s}^{-1}$
• B. $2160kgm{s}^{-1}$
• C. $3000kgm{s}^{-1}$
• D. $1080kgm{s}^{-1}$

Answer 1

The correct option is D

$1080kgm{s}^{-1}$

The algebraic sum of the moment of the system 3s later is,

$50(u-gt)=50(100-(5+3\left)9.8\right)=1080kgm{s}^{-1}$