A certain car is capable of accelerating at a rate of + 0.80 m/s2. How long does it take for this car to go from a speed of 15 mi/h to a speed of 75 mi/h?
Vo = 15mi/h * 1h/3600s * 1600m/mi=6.67 m/s = Inital velocity.
Vf = (75/15) * 6.67m/s = 33.33 m/s. = Final velocity.
t=(Vf-Vo)/a=(33.33-6.67) / 0.80=33.1 s.