physics
posted by riana on .
a car starts from rest , attains a velocity of 36kmph with an acceleration of 0.2m/s^2 travels 9km with this uniform velocity and then comes to halt with a uniform acceleration of 0.1m/s^2 find the total time of travel of the car.

v = 36 km/hr =36000/3600 = 10 m/s.
1. v =a1•t1, t1= v/a = 10/0.2 = 50 s.
2. t2 = s/v = 9000/10 = 900 s.
3. 0 = va•t3,
t3 = v/a2 = 10/0.1 = 100 s.
t(total) = 50+900+100 = 1050 s = 17.5 min.