A ball is dropped from the top of a tower of height 100 m and at the same time another ball is projected vertically upwards from ground with a velocity` 25 ms^(-1)` Then, the distance from the top of the tower, at which the two balls meet (take g=10m/s)

Options

A. `a)68.4 m`
B. b)`48.4 m`
C. c)`80 m `
D. d)`20 m`

Explanation

`t = ("height")/("speed") = (100)/(25) = 4s`
Fall, `h = ut + (1)/(2) g t ^(2)`
`h = 0 + (1)/(2) xx 9.8 xx 4 ^(2)`
`h = 8 xx 9.8 = 78.4 m`