Calculate the work to pump water out of tank

In summary, the problem involves finding the work needed to pump half the water out of a 2m long, 1m wide, and 1m deep aquarium filled with water. The density of water is given as 1000 kg/m3 and the acceleration due to gravity is 9.8 m/s2. Different methods, such as integrating with respect to dx or dy, can be used to solve this problem. However, when integrating F*D (where F is the force and D is the distance), the incorrect answer of 4900 J is obtained instead of the correct answer of 2450 J.
  • #1
bfpri
12
0
An aquarium 2 m long, 1 m wide, and 1 m deep is full of water. Find the work needed
to pump half the water out of the aquarium. (The density of water, p, is 1000 kg/m3,
and acceleration due to gravity, g, is 9.8 m/s2.)

So in order to truly understand how to do these kind of problems I decided to find different ways to solve this problem. Since you can integrate with respect to dx or dy, for dx i was wondering if you could integrate with respect to the 2m side like so

*edit..ugh its not letting me post the pictures so i'll just give the link...http://img19.imageshack.us/img19/2024/boxid.gif

In order to get the answer i integrated F*D. F=p*g*volume=pg(1); D=1-x

integral((1-x)(1)pgdx) from x=0 to x=1. But when i do, i get the wrong answer, 4900 J. The answer should be 2450 J =/
 
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  • #2
bump.
 

1. How do you calculate the work required to pump water out of a tank?

To calculate the work required, you need to know the weight of the water in the tank, the height the water needs to be pumped, and the efficiency of the pump. The formula for work is: work = weight x height x efficiency.

2. What is the weight of water in a tank?

The weight of water can be calculated by multiplying the volume of water by its density. The density of water is typically 1000 kg/m³.

3. How do you determine the height the water needs to be pumped?

The height the water needs to be pumped is the vertical distance between the top of the water level in the tank and the discharge point. This can be measured using a measuring tape or by calculating the difference in elevation between the two points.

4. What is the efficiency of a pump?

The efficiency of a pump is the ratio of output energy to input energy. It is typically expressed as a percentage and can be affected by factors such as the type of pump, its condition, and the properties of the fluid being pumped.

5. Can the work required to pump water out of a tank be reduced?

Yes, the work required can be reduced by using a more efficient pump, reducing the height the water needs to be pumped, or decreasing the weight of the water in the tank. Regular maintenance of the pump can also help maintain its efficiency.

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