How many hydraulic rams do I need to prevent wall collapsing ?

[davekardle]

Homework Statement

rectangle wall with 3m height, 20 length, 6.0m width.
Rectangle filled with water.

The Attempt at a Solution

I've calculated the force acting on the wall to be: 1766 KN

I have a hydraulic ram exerting 5 tonnes of pressure.

How many do I need ?

Homework Equations

F=P.A

 

[rude man]

Average pressure = ρgd, d = 3m, g = 9.81 m-s^(-2), ρ = 1e3 kg/m^3.

So you know the force on each wall is ρAgd/2 assuming the walls can sustain max pressure of twice average pressure without breaking apart.

1 tonne = 1000kg*g of force. (It is not a measure of pressure but of force.)

The rest is 1st year high school algebra.

 

[davekardle]

Average pressure = ρgd, d = 3m, g = 9.81 m-s^(-2), ρ = 1e3 kg/m^3.

So you know the force on each wall is ρAgd/2 assuming the walls can sustain max pressure of twice average pressure without breaking apart.

1 tonne = 1000kg*g of force. (It is not a measure of pressure but of force.)

The rest is 1st year high school algebra.

That's exactly what I did:

Here's how I done:

F on each wall= (1766KN)

1T/m^2 = 9800 pa
5T/m^2 = 49000 pa

Force exerted by the hydraulic ram on the wall = 49000 X ( Depth x width ) = 882 KN for each Hydraulic ram.

So, to resist an opposite force of 1766KN I will need 2 Hydraulic rams.


Is this right ? thanks

 

[rude man]

F on each wall= (1766KN)

The force on two of your walls is greater than that on the other two since your room is not square-shaped.