A  car travelling at 58km/hr overtakes another car travelling at 40 km/hr. Assuming each car to be 5m long, calculate the time taken for overtaking.

According to the question, 

Relative speed of the cars = (58 - 40)= 18 km/h = 5 m/s

Relative distance to cover while overtaking,

d = (5+5) = 10 m

Time  for overtaking = 10/5 = 2 sec