posted by Marnal .
A motor car in rectilinear motion steadily decelerates to rest in 20s.Using Newton's second law of motion,explain why a higher force is required to stop the car in 10s than in 20s.
Acceleration is velocity change DIVIDED BY time.
Stopping in less time requires greater acceleration, a.
F = m a
So it also requires more force. Twice as much, in this case.