An object moves the first half of the total distance with a speed of 2 m `s^(-1)`. If the average speed of the body is 3 m `s^(-1)`, the speed of the body when it trav elled the remaining distance is ________ m `s^(-1)`

Options

A. 3
B. 6
C. 4
D. 2

Answer

B

Explanation

Let the total distance be 2d.
Then,
`(d)/(t_(1))=2 " " (1)`
`(d)/(t_(2))=x`,
`(2d)/(t_(1)+t_(2)) =3 rArr d= (3(t_(1)+t_(2)))/(2)" "(2)`
From (1) and (2).
`2t_(1)=3((t_(1)+t_(2)))/(2) rArr 4t_(1) = 3t_(1) +3t_(2)`
`t_(1)=3t_(2) :. (d)/(t_(1)//3)=x rArr (3d)/(t_(1))=x`
From (1),
`3(2)=x`
`x=6 ms^(-1)`