A 5.0 kg model vehicle travelling at 14 m/s experiences a rocket boost of 85 N ( in the direction of motion) for 20 s

What is the resulting speed?
The answer is 350 but i don't know how to get to that answer

1 answer

a = F/m = 85/5 = 17 m/s^2.

V = Vo + a*t = 14 + 17*20 = 354 m/s.