How to calculate potential energy of water in a tank?

In summary, to calculate the potential energy of water in a cylindrical tank filled to a height of h, with a total mass of M, use the equation U = 1/2mgh, where g is the gravitational acceleration, y is the water level from the base, A is the area of the water surface, and r is the water density. This equation can also be written as dU = grAydy.
  • #1
fuzzylogic
8
0
Suppose you have a cylindrical tank of water that is filled to height h. Total mass of water is M. How do you calculate the potential energy of water relative to the base of the tank?
 
Physics news on Phys.org
  • #2
fuzzylogic said:
Suppose you have a cylindrical tank of water that is filled to height h. Total mass of water is M. How do you calculate the potential energy of water relative to the base of the tank?

Welcome to the PF.

What is the context of the question? What do you intend to use the PE for?
 
  • #3
I just want to know what the stored p.e. is
 
  • #4
fuzzylogic said:
I just want to know what the stored p.e. is

How come? And how did the water get into the tank? And where is it going to go as it flows out of the tank?

PE is relative to something, it is not an absolute quantity. It is valid to say that the stored PE of water in a tank is zero. And then if the water flows out to some other tank, there may be a change in the stored PE...
 
  • #5
does this make sense:
g=gravitational acc
y=water level from base
A=area of water surface
r=water density
m=total mass of water
U=PE

then dU=grAydy
U=1/2grAh^2=1/2mgh (m=rAh)
 
  • #6
fuzzylogic said:
does this make sense:
g=gravitational acc
y=water level from base
A=area of water surface
r=water density
m=total mass of water
U=PE

then dU=grAydy
U=1/2grAh^2=1/2mgh (m=rAh)
Yes, that's fine.
 

1. How do I calculate the potential energy of water in a tank?

To calculate the potential energy of water in a tank, you will need to know the height of the water in the tank, the acceleration due to gravity, and the mass of the water. The formula for potential energy is PE = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height.

2. What is the unit of measurement for potential energy of water in a tank?

The unit of measurement for potential energy is joules (J). This is a standard unit for measuring energy.

3. Can potential energy of water in a tank be negative?

Yes, potential energy can be negative. This occurs when the height of the water is below the reference point, such as ground level. In this case, the potential energy would be considered as negative.

4. How does the potential energy of water in a tank affect the pressure?

The potential energy of water in a tank does not directly affect the pressure. However, as the height of the water increases, so does the pressure at the bottom of the tank due to the weight of the water above it.

5. Is the potential energy of water in a tank constant?

No, the potential energy of water in a tank is not constant. It changes as the height of the water in the tank changes. As the water is used or added to the tank, the potential energy will also change accordingly.

Similar threads

Replies
34
Views
2K
Replies
22
Views
5K
  • Introductory Physics Homework Help
Replies
5
Views
398
Replies
7
Views
1K
Replies
2
Views
1K
  • Classical Physics
Replies
3
Views
703
  • Introductory Physics Homework Help
Replies
22
Views
2K
Replies
50
Views
3K
Replies
12
Views
2K
Back
Top