Given initial velocity of stone, u = 5 m `s^(-1)`

Downward of negative Acceleration, a = 10 m `s^(2)`

We know that 2 as = `v^(2)-u^(2)`

Therefore, Height attained by the stone, `s=(0^(2))/(5^(2))xx(-10) m`

=`(-25)/(-20) m `

= 1.25 m

Also we know that final velocity, v = u + at

or, Time, `t=(v-u)/(a)`

Therefore, Time, t taken by stone to attain the height, s `(0-5)/(-10s)`

= 0.5 s