Speeds of two identical cars are u and 4u at a sufficient instant. What is the ratio of the respective distance at which the two cars are stopped from

Explanation:

The velocity of the first car can be written as 

u₁²=2as₁

⇒s₁=u² / 2a

And for second car

u₂²=2as₂

s₂=(4u)² / 2a

The two car stopped 

s₁:s₂ = 1:16