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Question
A car travelling at 60 km/h overtakes another car travelling at 42 km/h. Assuming each car to be 5.0 m long, find the time taken during the overtake and the total road distance used for the overtake.
Solution
Velocity of the first car, v1 = 60 km/h = 16.7 m/s
Velocity of the second car, v2 = 42 km/h = 11.7 m/s
Relative velocity between the cars = (16.7 − 11.7) = 5 m/s
Distance travelled by the first car w.r.t. the second car = 5 + 5 = 10 m
Time,
The first car also covers a distance equal to its own length = 5 m
∴ Total road distance used for the overtake = 33.4 + 5 ≈ 38 m
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