A vehicle is moving on a highway at a speed of 60 kmph. The coefficient of friction between the road surface and the tyres is 0.35 and the reaction time of the driver is 2.5 sec. Estimate the lag distance.
- A39.7 m
- B40.7 m
- C41.7 mCorrect
- D42.7 m
Solution
Concept
Stopping sight distance
Formula
lag = v t
Step-by-step solution
1. v = 60/3.6 = 16.67 m/s. 2. Lag distance = 16.67 × 2.5 = 41.7 m.
Explanation
The lag distance is travelled during the reaction time.
Why the other options are wrong
Braking distance is not asked.
Shortcut
v × t.
Correct answer: C) 41.7 m