GATE 2016 CE (CE2) – Question 64
A motorist traveling at 100 km/h on a highway needs to take the next exit, which has a speed limit of 50 km/h. The section of the roadway before the ramp entry has a downgrade of 3% and coefficient of friction ( f ) is 0.35. In order to enter the ramp at the maximum allowable speed limit, the braking distance (expressed in m) from the exit ramp is _________
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Correct answer: 92 to 93
Explanation
A downgrade reduces effective braking resistance to f−G=0.35−0.03=0.32. For speeds in km/h, braking distance is(V1²−V2²)/[254(f−G)]. Thus distance=(100²−50²)/(254·0.32)=**92.27m**. Reaction distance is excluded because only braking distance is requested.