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Mechanics 1 Question : Momentum HELP!

A bullet is fired by a gun which is 4kg heavier than the bullet. Immediately after the bullet is fired, it is moving with speed 200ms^-1 and the gun recoils in the opposite direction with speed 5ms^-1.

Find the mass of the bullet

Reply 1

username3671216

since there is conservation of momentum,
the recoil velocity of gun x mass of gun = mass of bullet x speed of the bullet.
Let the mass of the bullet be m.
Please work out from here.

(edited 6 years ago)

Reply 2

old_engineer

Original post by SumOfSquares

since there is conservation of momentum,
the recoil velocity of gun x mass of gun = mass of bullet x speed of the bullet.
Let the mass of the bullet be m.
Therefore,
5x (4+m) = 200x m
20 + 5m = 200m
20 = 195m
Therefore m = 20/195 kg = 0.10 kg to 2dp