A person holding a 15.0 kg gun containing one 50.0 g bullet is riding on a train that is traveling at 75.0
km/h East. If the man fires the gun and the bullet moves with a velocity of 350 m/s East (relative to
the train), what is the velocity of the gun relative to the ground?

Question

A person holding a 15.0 kg gun containing one 50.0 g bullet is riding on a train that is traveling at 75.0 
km/h East. If the man fires the gun and the bullet moves with a velocity of 350 m/s East (relative to 
the train), what is the velocity of the gun relative to the ground?

anonymous · Answer

so i got 19.7 m/s west               using the conservation of momentum formula for linear collisions.               however it said relative to the ground so im not sure if theres an extra step in there.

anonymous · Answer

The bullet and train are moving the same direction so before the bullet is shot it is already traveling at 75 km/h east. Just add the two velocities.