Answer:
1:281.25m
2:75m/s
Explanation:
using the equation
[tex]v^{2} = u^{2} + 2gs[/tex]
at maximum height v is zero so using that you can make s the subject of the formula
[tex]h \: max = u^{2} \div \: 2g[/tex]
so substitute the velocity 75 and the constant g-10m/s^2
as for the returning velocity we say displacement is zero since you go and come back the same distance
so
[tex]v = { + or - }u[/tex]
u is the initial speed in this case it's positive since going in the direction of gravity