Question

Stopping distance of a moving vehicle is directly proportional to

• A. Square of the initial velocity
• B. Square of the initial acceleration
• C. The initial velocity
• D. The initial acceleration

Answer 1

Answer: (A)

Square of the initial velocity

Answer 2

Let d, is the distance travelled by the vehicle before it stops.

Here, final velocity v = 0, initial velocity = u, S = d, Using equations of motions

$\mathrm { v } ^ { 2 } = \mathrm { u } ^ { 2 } + 2 \mathrm { as }$

$\therefore ( 0 ) ^ { 2 } = \mathrm { u } ^ { 2 } + 2 \mathrm { ad }$

$d _ { s } = \frac { u ^ { 2 } } { 2 a }$

$\mathrm { d } _ { \mathrm { s } } \propto \mathrm { u } ^ { 2 }$