Question

The stopping distance of vehicle is 3 m when its speed of driving is 5 m/s. What will be the stopping distance for the same vehicle if its speed is tripled (three times) ? [ Ans. 27 m ]

Answer 1

Answer:

Explanation:

Work done = kinetic energy

Work done = braking force × distance

This means that:

So for a fixed maximum braking force, the braking distance is proportional to the square of the velocity.

Answer 2

Answer:

27

Explanation:

Given, u=5 m/s

v=0

s=3m(at least)

By third equation by motion,

v2=u2+2as=(5×5)+2(−a)(3)=25-6a=

a= 4.17

Now applying third equation of motion,

v2=u2+2as⟹0=(15)2+2(−4.17)(s)⟹0=225−8.34s⟹s=26.970≈27.00