a)
Acceleration of stone = 10
Integrate:
So velocity = 10t
Integrate again:
So distance from starting point = 5t^2
Distance from ground = 450-5t^2
b)
450 - 5t^2 = 0
9.48 seconds
c) velocity = 10t
Put the time into this to give:
94.8 m/s
d.
Velocity = 10t + 5
Integrate again:
5t^2 + 5t
Solve
5t^2 + 5t = 450
Gives 9 seconds