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GATE 2018 CE (CE2) – Question 45

Transportation Infrastructure · Geometric design of roadways: cross-section, sight distance, alignments · 2 marks · Multiple choice

A car follows a truck at 10 m/s on a two-lane, two-way road, 16 m behind it. With a clear opposing gap, the car accelerates at an average 4 m/s², overtakes and returns to its lane 16 m ahead of the truck. The car distance from leaving to returning to its lane is ______.

  1. 64 m
  2. 72 m
  3. 128 m
  4. 144 m

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Correct answer: (B) 72 m

Explanation

The car must gain $16+16=32$ m relative to the truck. Vehicle lengths are not supplied and are neglected in the keyed model. With zero initial relative speed, $32=4t^2/2$, hence t = 4 s. Car distance is $10(4)+4(4^2)/2=72$ m (B).