Answer:
Final momentum is double the initial momentum
Explanation:
Momentum, p is given by, p=mv where m is mass and v is velocity of an object. From law of conservation of linear momentum, the sum of initial and final momentum are equal. In this case, let initial mass be m and final mass will be 0.5 m since it losses half its mass. Also, let initial velocity be v and final velocity will be 4v
Initial momentum= mv
Final momentum= 0.5m*4v=2mv
The final momentum is twice the initial momentum.
