A(n) 10000 kg freight car is rolling along a

track at 4.6 m/s.
Calculate the time needed for a force of
1670 N to stop the car.
Answer in units of s.

F = ma, so a = F/m = 1670/10000 = 0.1670 m/s^2

4.6 - at = 0
t = 4.6/0.1670 = ____ s