a gun fires a shell of mass 3 kg in a horizontal direction the gun recoils with velocity of 5m/s and its mass 6 kg . calculate the velocity of the shell
Answers
Given :
- Mass of gun = 6kg
- Recoil velocity of gun = 5m/s
- Mass of shell = 3kg
To find :
Velocity of shell { = v (let) }
Formula used :
Linear momentum = mass × velocity
Solution :
Initially ,
velocity of gun = velocity of shell = 0
Therefore,
➝ Initial momentum of gun = 6×0 = 0
➝ Initial momentum of shell = 3×0 = 0
➝ Total initial momentum = Initial momentum of gun + Initial momentum of shell
➝ Total initial momentum = 0
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Finally,
As , we are given recoil velocity of gun, which is negative of velocity of gun
this means , velocity of gun = -5m/s
➝ Final momentum of gun = 6×(-5) = -30m/s
➝ Final momentum of shell = 3×v
➝ Total final momentum = Final momentum of gun + Final momentum of shell
➝ Total final momentum = -30 + 3v
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According , to law of conservation of linear momentum
Initial momentum = Final momentum
➝ 0 = 3v - 30
➝ 3v = 30
➝ v = 30÷3
➝ v = 10 m/s
ANSWER :
Velocity of shell = 10 m/s