Question

a bullet of mass 0.2 kg is fired from gun weighing 7.5kg. if the initial velocity of the bullet is 200ms,calculate the speed with which the gun reciols

Answer 1

Answer :

Mass of bullet = 0.2kg

Mass of gun = 7.5kg

Speed of bullet = 200m/s

We have to find recoil speed of gun$.$

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In case of bullet firing from gun, total momentum of whole system is conserved since no net force acts on the system.

Initial momentum of system = zero

Therefore final momentum of system must be zero.

➝ Final momentum = 0

➝ MV + mv = 0

➝ V = -mv/M

V denotes recoil speed of gun

M denotes mass of gun

m denotes mass of bullet

v denotes speed of bullet

➝ V = -mv/M

➝ V = -(0.2 × 200)/7.5

➝ V = -40/7.5

➝ V = -5.33m/s

[Note : -ve sign shows opposite direction]

Answer 2

Answer:

Mass of bullet = 0.2kg

Mass of gun = 7.5kg

Speed of bullet = 200m/s

We have to find recoil speed of gun..

_________________________________

In case of bullet firing from gun, total momentum of whole system is conserved since no net force acts on the system.

Initial momentum of system = zero

Therefore final momentum of system must be zero.

➝ Final momentum = 0

➝ MV + mv = 0

➝ V = -mv/M

V denotes recoil speed of gun

M denotes mass of gun

m denotes mass of bullet

v denotes speed of bullet

➝ V = -mv/M

➝ V = -(0.2 × 200)/7.5

➝ V = -40/7.5

➝ V = -5.33m/s

[Note : -ve sign shows opposite direction]