Question

From a Rifle of mass 8 kg a bullet of mass 100 g is fired with an initial velocity of 70 m/s. Calculate the recoil velocity of

Rifle.​

Answer 1

Answer:

Explanation:

Initial momentum of the system  P  

i

​  

=0

Given:  M  

bullet

​  

=0.02 kg      V  

bullet

​  

=100 m/s         M  

gun

​  

=8 kg

Let the recoil velocity of gun be V.

Applying the conservation of linear momentum :  P  

f

​  

=P  

i

​  

 

Or   M  

gun

​  

V+M  

bullet

​  

V  

bullet

​  

=0

Or   8V+0.02×100=0

⟹ V=−0.25 m/s

Answer 2

Answer:

Initial momentum of the system P

i

=0

Given: M

bullet

=0.02 kg V

bullet

=100 m/s M

gun

=8 kg

Let the recoil velocity of gun be V.

Applying the conservation of linear momentum : P

f

=P

i

Or M

gun

V+M

bullet

V

bullet

=0

Or 8V+0.02×100=0

⟹ V=−0.25 m/s