A car of length 4m wants to overtake a trailer truck of length 20m travelling at 36km hr within 10 s...........

Explanation:

Given :
car of length = 4 m
length of truck = 20 m
Speed of truck = 36 km/hr
Approach:
Total distance to be covered by the car 'd' = 20 + 4 = 24 m
Let speed of car be S1 m/s
Speed of truck S2 = 36 km/hr = 10 m/s
Both the car and the truck are travelling in the same direction and we know that to overtake the truck,
the speed of the ca should be more than that of the truck.
Hence, relative speed = |S1 - S2|
Time to overtake = 10s
S = d/t
|S1 - 10| = 24/10
S1 - 10 = 2.4
S1 = 10 + 2.4 = 12.4 m/s