Hi

I need to know how much ground water presuure would be required to lift a 1.200m diameter plastic tank weighing 650kg out of the ground please,
Please supply the answer in Kpa or psi
Cheers

4 answers

How is the cylinder oriented? Axis pointing down?
Yes
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The oreientation of the tank needed to be specified. The ground water gauge pressure at the bottom multiplied by the cylinder area must equal the weight, neglecting friction at the sides.

P*pi*D^2/4 = 650 kg*(9.8 m/s^2)

P = 5630 N/m^2 = 5.6 kPa

Ground water gauge pressure will be determined by the length of the cylinder. This assumes that the tank is above the aquifer. Otherwise there will be no ground water pressure.
Hi Drwls
If the tank is standing up i.e 1.200 dia x 1.100 high with 650 kg inside, would the water pressure to lift it be the same
Cheers