Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 4.8-kg projectile from rest to a speed of 3.9 103 m/s. The net force accelerating the projectile is 4.8 105 N. How much time is required for the projectile to come up to speed?

Answer 1

a=F/m
v=at=Ft/m =>
t=mv/F