# How to lift water out of a pool

• TheStig
In summary, to find the amount of work needed in joules to lift the water out of the pool, we use the formula work = integral {0 to depth of water} (density of water * gravitational acceleration * pi * (diameter/2)^2 * (pool height - y))dy. This results in a value of 2.47 * 10^6 joules.
TheStig

## Homework Statement

given, diameter and height of pool, depth of water, density of water and gravitational acceleration.
g = 9.8
height is 4m
2r = 20m
depth of water = 3.5m
density =1000kg/m^3
So, I'm supposed to find how much work is needed in joules to lift the water out of the pool.

## Homework Equations

could I use density times gravity times volume to get my force?
is my distance for my water to travel 4.5m?

## The Attempt at a Solution

Anyways, I've tried to use my volume for the pool and the volume I have of water * density *gravity to come up with my force and then used 4.5m as my distance to come up with my work needed to lift water out of a pool. I ended up with 1.08E7 joules but that's incorrect so any help would be appreciated.

BTW, this is a cal 2 problem/integration problem

if it is a cal2/integration problem why aren't you doing any integration? do you know the formula for work?

Use the volume of the water and the density to get mass. It would appear that the pool is a right circular cyliner.

Rasining a mass m some distance h in a gravity field producing a local acceleration g increases the potential energy by mgh.
could I use density times gravity times volume to get my force?
Yes

is my distance for my water to travel 4.5m?
Well that depends, if one is lifting the CM of the pool water 4 m or (4 m + 1.75 m) or 5.75 m, which is 4 m from the top of the pool.

I've tried integrating it and I've tried astronuc's advice with no success, any ideas?

Last edited:
I'm retarded, integration works. Alright, so with a mixture of the advice, correct answer is 2474002 joules. Thanks again fellas.

weight density = 9800 N/m^3

work = integral {0 to 3.5} (9800)(pi*10^2)(4 - y)dy

work = 2.4 * 10^7 Joules

## 1. How do I use a pool pump to lift water out of my pool?

The first step in using a pool pump to lift water out of your pool is to make sure the pump is in good working condition. Next, connect the pump to a drain hose and place the other end of the hose in the area where you want to empty the water. Then, turn on the pump and it will begin to lift the water out of the pool and into the drain hose.

## 2. Can I use a sump pump to lift water out of my pool?

Yes, a sump pump can also be used to lift water out of a pool. Similar to a pool pump, you will need to connect the sump pump to a drain hose and place the other end in the desired drainage area. Then, turn on the sump pump and it will remove the water from the pool.

## 3. How long does it take to lift all the water out of a pool?

The time it takes to lift all the water out of a pool will depend on the size of the pool, the strength of the pump, and the flow rate of the water. Generally, it can take anywhere from a few hours to a full day to completely empty a pool using a pump.

## 4. What should I do with the water once it has been lifted out of the pool?

The water can be drained into a nearby sewer or storm drain, or it can be used to water plants or grass in your yard. It is important to check with your local regulations before disposing of the water to ensure it is done properly.

## 5. Can I manually lift water out of my pool without a pump?

It is possible to manually lift water out of a pool using a bucket or siphon, but it can be a time-consuming and labor-intensive process. It is recommended to use a pump for more efficient and effective water removal.

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