A body is thrown vertically upward from a point `A` 125 m above the ground. It goes up to a maximum height of 250 m above the ground and passes through `A` on its downward journey. The velocity of the body when it is at a height of 70 m above the ground is `(g=10 m//s^(2))`

Options

A. `50 ms^(-1)`
B. `60 ms^(-1)`
C. `80 ms^(-1)`
D. `20 ms^(-1)`

Answer

B

Explanation

`v_(A) = sqrt(2gh)` here `h= 125 m`
Velocity at a distance `55 m` below 'A' is
`v^(2) = v_(A)^(2) + 2gh_(1)` here `h_(1) = 55 m`.