Question

a bullet of mass 30g is fired from a gun with a velocity 116m/s . if the recoil velocity of the gun is 2m/s , then what is the mass of the gun?​

Answer 1

Given:-

→Mass of the bullet(m)=30g

→Velocity of the bullet(v)=116m/s

→Recoil velocity of the gun(V)=2m/s

To find:-

→Mass of the gun(M)

Solution:-

Here,we can see that the mass of the bullet is given in gram(g). So firstly,we shall convert the mass of the bullet from gram(g) to kilogram(kg).

=>1g=0.001kg

=>30g=30(0.001)

=>0.03kg

By using Law of Conservation of momentum,we get:-

=>M(-V)+mv=0

=>M=mv/V

=>M=0.03×116/2

=>M=1.74kg

Thus,mass of the gun is 1.74kg.

Some Extra Information:-

Conservation of momentum:-

We have studied the equation,

=>F=mv-mu/t

=>Fext=mv-mu/t. (Since,F=Fext)

=>Fext×t=mv-mu

When external force is 0:-

=>0×t=mv-mu

=>mv-mu=0

=>mv=mu

=>Thus,Initial momentum=Final momentum

=>Change in momentum is 0,i.e.

momentum remains conserved.

From above we can infer that "When external force acting on a system is zero,the total momentum of the system remains constant/conserved".

Answer 2

Explanation:

Given:-

→Mass of the bullet(m)=30g

→Velocity of the bullet(v)=116m/s

→Recoil velocity of the gun(V)=2m/s

To find:-

→Mass of the gun(M)

Solution:-

Here,we can see that the mass of the bullet is given in gram(g). So firstly,we shall convert the mass of the bullet from gram(g) to kilogram(kg).

=>1g=0.001kg

=>30g=30(0.001)

=>0.03kg

By using Law of Conservation of momentum,we get:-

=>M(-V)+mv=0

=>M=mv/V

=>M=0.03×116/2

=>M=1.74kg

Thus,mass of the gun is 1.74kg.

Some Extra Information:-

Conservation of momentum:-

We have studied the equation,

=>F=mv-mu/t

=>Fext=mv-mu/t. (Since,F=Fext)

=>Fext×t=mv-mu

When external force is 0:-

=>0×t=mv-mu

=>mv-mu=0

=>mv=mu

=>Thus,Initial momentum=Final momentum

=>Change in momentum is 0,i.e.

momentum remains conserved.

From above we can infer that "When external force acting on a system is zero,the total momentum of the system remains constant/conserved".

hope this helps you!!

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