Question

A body is allowed to fall from a height of `100 m`. If the time taken for the first `50 m` is `t_1` and for the remaining `50 m` is `t_2` then :
A. `t_1 = t_2`
B. `t_1 gt t_2`
C. `t_1 lt t_2`
D. depends upon the mass.

Answer 1

Correct Answer - B
`s = (1)/(2) g t_1^2`
or `t_1^2 = (50 xx 2)/(g) = (100)/(g)` or `t_1 = (10)/(sqrt(g))`
and `100 = (1)/(2) g t^2`or `t = (10 sqrt(2))/(sqrt(g))`
`t_2 = t - t_1 = (10)/(sqrt(g)) (sqrt(2) - 1) = 0.4 t_1`
`t_1 gt t_2`.