Question On fluid mechanics

[alamin]

A cylindrical tank of diameter 90 cm rests on top of a platform 6m
high. Initially the tank is filled with water to a depth of 3m. A plug
whose are is 3 cm^2 is removed from the orifice on the side of the
tank at the bottom.

1) at what speed will water strike the ground?
11) how long will it take for the tank to be empty?

[Galileo]

What are your thoughts on this? Anything you got so far?

[alamin]

Yeah, for part one:
H=0.5gt^2
t^2 = 12/9.8
t= (12/9.8)^.5

v=u +at
v= 0 + (12*9.8)^0.5
this we could acheive

But for part 2:
Velocity of eflux changes with time. thus
D(vol)/Dt = A*(2gh)^.5 = ((Pi*d^2)/4)*dh/dt
Is this correct?