Question

If similar bullets are fired from two guns out of which one is lighter and another one is heavier. Which gun will give more violent jerk?

• A. Same by both
• B. Lighter one
• C. Heavier one
• D. Will depend upon the type of gun

Answer 1

The correct option is C Heavier one

Let us assume two things.

1. Mass of both bullets is same.
2. Muzzle velocity of both bullets is same.

In such a case the momentum of the bullet in both case will remain same.

Now reverse momentum on the shoulder will also be same owing to conservation of momentum.

But the jerk the shoulder will have to withstand will depend on the velocity the gun will take. And here come basic math.

P or momentum is same.

M or mass is the of rifle.

Hence v or velocity is nothing but p/m. Hence lower the m higher the v and vice versa.

So the rifle with lower mass will revert back with higher velocity.