Question

5 bullets each of mass 1Ogm per second fired
vertically up such that a plate of mass 200 gm floats
in air. If bullets rebounds with same velocity back
vertically down velocity with which each bullet is fired
in ms'is (g-10ms)​

Answer 1

Answer:

The mass of plate is M = 200 g = 0.2 kg

The mass of bullet is m = 10 g = 0.010 kg

The bullets are fired at a rate of 10 bullets per second.

Let v be the speed of each bullet.

After colliding with the plate, they rebound with same speed.

Thus, rate of change in momentum of the bullets, that is, the force exerted by bullets is

2 v × 0.010 × 10

This balances the weight of the plate.

2 v × 0.010 × 10 = 0.2 × 9.8

v = 9.8 m/s