A car requires velocity of 36 km/h in 10sec just after the start . It takes 20sec to stop . Calculate the acceleration in both the cases .

V = 36km/h = 36000m/3600s = 10 m/s.

V = Vo + a*t = 10 m/s.
0 + a*10 = 10, a = 1 m/s^2.

V = Vo + a*t = 0.
10 + a*20 = 0, 20a = -10, a = -0.5 m/s^2.