Correct Answer - Option 3 : 0.5
Concept:
Braking Distance:
It is the distance travelled by vehicle after the application of brakes.
Skid length or braking distance is given by, \({\rm{L}} = \frac{{{{\rm{u}}^2}}}{{2{\rm{gf}}}}\),
where u is the velocity of the vehicle in m/s, f is the actual coefficient of friction mobilized and g is the acceleration due to gravity.
Calculation:
Given,
Velocity of vehicle (u) = 127 kmph = 127/3.6 = 35.278 m/s
Braking distance (L) = 127 m
∴\({\rm{L}} = \frac{{{{\rm{u}}^2}}}{{2{\rm{gf}}}}\)
⇒ \({\rm{127}} = \frac{{{{\rm{35.278}}^2}}}{{2\ \times \ {\rm{9.81 \times f}}}}\)
f = 0.4994 ≈ 0.5
