Question

A 2gm bullet is fired from a 2kg rifle with a velocity of 200m/sec North wards, the recoil velocity of the rifle is
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Answer 1

Explanation:

Given:-

A 2gm bullet is fired from a 2kg rifle with a velocity of 200m/sec North wards.

To find:-

Find the recoil velocity of the rifle ?

Solution:-

Mass of the bullet = 2 gm

Mass of the rifle = 2kg

Velocity = 200 m/sec

We know that

The external force = 0

Since for The firle and bullet system

The momentum Conservation =

Initial momentum = Final mimentum

We have m = 2 gm = 2/1000 kg = 2×10^-3 kg

and u = 200 m/sec and M = 2kg

Mv +mu = 0

=>2v + 2×10^-3×200 = 0

=>2v +(2/1000)×200 = 0

=>2v +(400/1000)=0

=>2v + (4/10)=0

=>2v + 0.4 = 0

=>2v = -0.4

=>v = -0.4/2

=>v = -0.2 or -2×10^-1 m/sec

v = - 0.2 m/sec or -2×10^-1 m /sec

Here negative sign represents the velocity of rifle is opposite to that of the bullet.

Answer:-

The recoil velocity if the rifle is -0.2 m/s or -2×10^-1 m/s