Calculating Fluid Eflux: The Impact of a Cylindrical Tank on a Platform

Click For Summary
The discussion focuses on calculating the speed of water eflux from a cylindrical tank and the time it takes for the tank to empty. The initial height of water is 3m, and the tank is 6m high, with a plug area of 3 cm² removed. For the speed of the water striking the ground, the participants reference the equation H=0.5gt² to determine the time and subsequently the velocity. The second part addresses the changing velocity of eflux, suggesting the use of the equation D(vol)/Dt = A*(2gh)^(0.5) to find the rate of change of volume over time. The conversation emphasizes the need for accurate calculations to determine both the speed and the time for the tank to empty.
alamin
Messages
8
Reaction score
0
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?
 
Physics news on Phys.org
What are your thoughts on this? Anything you got so far?
 
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 achieve

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?
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
Replies
50
Views
7K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 24 ·
Replies
24
Views
4K
Replies
8
Views
3K
  • · Replies 49 ·
2
Replies
49
Views
5K
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K