Question -
Answer -
The speed of car A =36 km/h = 36 x (5/8) = 10 m/s
Speed of car B = 54km/h = 54 x (5/18) = 15 m/s
Speed of car C =– 54 km/h = -54 x (5/18) = -15 m/s (negative sign shows B and C are inopposite direction)
Relative speed of Aw.r.t C, VAC= VA – VB = 10 – (-15) =25 m/s
Relative speed of Bw.r.t A, VBA = VB – VA = 15 –10 = 5 m/s
Distance between AB =Distance between AC = 1 km = 1000 m
Time taken by the carC to cover the distance AC, t = 1000/VAC = 1000/ 25 = 40 s
If a is the acceleration,then
s = ut + (1/2) at2
1000 = (5 x 40) +(1/2) a (40) 2
a = (1000 – 200)/ 800= 1 m/s2
Thus, the minimumacceleration of car B required to avoid an accident is 1 m/s2