Question

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 7.9-kg projectile from rest to a speed of 2.8 × 103 m/s. The net force accelerating the projectile is 6.7 × 105 N. How much time is required for the projectile to come up to speed?

Answer 1

F=ma
v = at = Ft/m
so,
t = vm/F = 2.8*10^3*7.9 /6.7*10^5 = 0.033 seconds