Laws Of Motion Question 255
Question: N bullets each of mass m kg are fired with a velocity $ vm{{s}^{-1}} $ at the rate of n bullets per second upon a wall. The reaction offered by the wall to the bullets is given by
Options:
A) nmv
B) $ \frac{Nmv}{n} $
C) $ n\frac{Nm}{v} $
D) $ n\frac{Nv}{m} $
Show Answer
Answer:
Correct Answer: A
Solution:
Total mass of bullets = Nm, time $ t=\frac{N}{n} $
Momentum of the bullets striking the wall = Nmv Rate of change of momentum (Force) = $ \frac{Nmv}{t} $ = nmv.
