A car accelerates from rest at constant rate for the first 10 s and covers a distance x. It covers a distance y in the next 10 s at the same acceleration. Which of the following is true?

Options

A. x=3y
B. y=3x
C. x=y
D. y=2x

Answer

b

Explanation

Let acceleration acting in both cases be a
Motion from A to B
`x=ut+(1)/(2)at^(2)`
`x=0+(1)/(2)a(10)^(2)=50a`
Again `v_(1)=u+at`
`v_(1)=10a`
Motion from B to C
`y=v_(2)t+(1)/(2)at^(2)`
`=10at+(1)/(2)at^(2)`
`=100a+(1)/(2)a(100)`
`y=150a`
Divide equation i by ii
`(x)/(y)=(50a)/(150a)`
`y=3x`