A balloon starts rising from the ground with an acceleration of `1.25ms^-2`. After 8 seconds, a stone is released from the balloon. After releasing, the stone will:

Options

A. cover a distance of 40 m
B. have a displacement of 50 m
C. reach the ground in 4s
D. begin to move down after

Answer

3

Explanation

`S=(1)/(2)(a)(t)^(2)`
`=(1)/(2)(5/4)(8)^(2)`
`=40 m`
and v= at
`=(5)/(4) (8)=10 m//s`
`and-40 = 10t-(1)/(2) gt^(2)`
`t^(2)-2t-8=0`
`t=4 sec`