Question

An automobile, travelling at 40 km/h, can be stopped at a distance of 40 m by applying brakes. If the same automobile is travelling at 80 km/h, the minimum stopping distance, in metres, is ______. (assume no skidding)

Options

• 75 m 

• 160 m

• 100 m 

• 150 m

Answer 1

An automobile, travelling at 40 km/h, can be stopped at a distance of 40 m by applying brakes. If the same automobile is travelling at 80 km/h, the minimum stopping distance, in metres, is 160 m. (assume no skidding)

Explanation:

Here, s = `"v"^2/(2"a")` ⇒ s ∝ v²

 ⇒ s₂ = `"s"_1 ("v"_2/"v"_1)^2`

 ⇒ s₂ = `40(80/40)^2`

 ⇒ s₂ = 160 m