Question

N bullets each of mass m kg fired with a velocity v ms-1 at the rate of n bullets per second upon a wall . The reaction offered by the wall to bullets is given by

Answer 1

number of bullet = N
mass of each bullet = m
velocity of each bullet = v
time = 1sec

acceleration of each bullet = velocity per unit time = v
force applied by the bullet = ma = m×v
force applied by N number of bullets= nmv

by Newton's third law of motion, action is equals to reaction.
therefore, the reaction applied by the wall is equals to the action produced by the bullet

answer= Nmv