Question

A 100g bullet is fired from 10kg gun with the speed of 1000m/s what is speed of recoil of gun

Answer 1

Law of conservation of momentum M1*v1=M2*v2 10*v=0.1*1000 v=10m/sec

Answer 2

hey here is your answer,

mass of bullet  is m1= 100g=100/1000=0.1kg       [1g =1000kg

mass of gus is m2=10kg

before firing =velocity of bullet ,u1 =0

                    =velocity of gun ,u2 =0

after firing=velocity of bullet,v1= 100m/s

                =recoli velocity of the gun , v2= ?

total  momentum of the bullet and gun before fire  ,when the gun at rest is zero.

          m1u1 +m2v2=0

total momentum of the bullet and gun after firing

     = m1v1+m2v2

     =0.1kg * 100m/s +10kg *v2

      =1kgm/s +10kg*v2

    there is no external unbalanced force, so according to law of conservation of momentum,

total momentum after firing = total momentum before firing

=1kgm/s+10kg *v2 =0

=v2  = 1kgm/s / 10 kg

       = - 10kgm/s.

negative sign indicatesthat the direction in which the gun would recoil is opposite to that of bullet

i hope it helpful for u..