A vehicle accelerates from rest with a unifrom acceleration of 0.5m/s^2 up to a velocity of 36km/h.It travels at constant velocity for 1km,the brakes are then applied and it comes to rest in 20s.Calculate the total distance travelled and the total time taken.
V1 = 36,000m/3600s. = 10 m/s.
V1 = a*T1 = 10 m/s.
0.5*T1 = 10.
T1 = 20 s.
d1 = 0.5a*T1^2 = 0.5*0.5*20^2 = 100 m.
d2 = V1*T2 = 1000 m.
10 * T2 = 1000.
T2 = 100 s.
V = V1 + a*T3 = 0.
a = -V1/T3 = -10/20 = -0.5 m/s^2.
V^2 = V1^2 + 2a*d3 = 0
d3 = -V1^2/2a = -(10^2)/-1 = 100 m.
d = d1+d2+d3 = 100 + 1000 + 100=1200 m.
T = T1+T2+T3 = 20 + 100 + 20 = 140 s.