# Ball Fountain Physics: Understand Equilibrium & Water Force

• krickon
In summary, the physics behind the ball fountain involve the principles of equilibrium and gravity. The weight of the ball is balanced by the pressure of the water shooting up from the pump. This pressure is calculated using the area of the ring and the weight of the ball. The water pressure acts in a normal direction on each part of the ball's surface, with the vertical component balancing the weight of the ball. With the right amount of pressure, the ball is lifted and the fountain works.
krickon
Hey! I have been looking over all these threads and have learned a lot. I was curious if anyone here could help me understand the physics of the ball fountain. I was thinking about the forces of the equilibrium with the weight of the granite ball and the water shooting up. I believe their is a thin film layer of water, maybe someone can help me better understand that. Thanks!

krickon said:
Hey! I have been looking over all these threads and have learned a lot. I was curious if anyone here could help me understand the physics of the ball fountain. I was thinking about the forces of the equilibrium with the weight of the granite ball and the water shooting up. I believe their is a thin film layer of water, maybe someone can help me better understand that. Thanks!

With all do respect, there is a reason why your question has not been answered yet :

1) specify your problem : what are you studying EXACTLY ?
2) What are your input data ? What data have been given ?
3) What are your strategies toward solving the problem ?
4) Which formula's are you going to use to do so ?
5) Show us some attempts and/or show us CLEARLY where you are having problems

good luck

greets marlon

Last edited:
marlon said:
With all do respect, there is a reason why your question has not been answered yet :

1) specify your problem : what are you studying EXACTLY ?
2) What are your input data ? What data have been given ?
3) What are your strategies toward solving the problem ?
4) Which formula's are you going to use to do so ?
5) Show us some attempts and/or show us CLEARLY where you are having problems

good luck

greets marlon

I am looking for any physics concepts that are involved with the weight of the ball being supported by the pressure of water. I decided to make one for myself. Here is all the information that I have for you.

Weight of ball- 11.5 lbs
Diameter of ball-8.270"
Ring is perfectly is shaped to ball
Water pump, pumps 1,521,360 ml per hour.
- I apoligize for the lack of information. I just would like to know the physics concepts that go along with the ball fountain.

Thanks again! Posts are greatly appreciated!

krickon said:
Ring is perfectly is shaped to ball
That seems quite unquantitative, after you decided to tell us the ball diameter to the thousandth of your unit. You ought to read the other ball fountain threads on this forum, for your explanation of the physics.

Last edited:
I haven't read much of the other threads, but it seems like one of the key items is to be sure that the pump can generate enough pressure to lift the ball. To figure that out, use the diameter of the ring and the weight of the ball to calculate the water pressure needed. Having a flow rate for the pump is not enough to know what pressure it can sustain.

Does anyone have a picture of what we are talking about here?

I have created a ball fountain, it works. I just would like to know what physics are behind it. What physics concepts are acting on this project. (equilibrium, gravity etc.)

krickon said:
I have created a ball fountain, it works. I just would like to know what physics are behind it. What physics concepts are acting on this project. (equilibrium, gravity etc.)

I think in the basic analysis, it is just the water pressure pushing on the underside surface of the ball that balances the weight of the ball (which comes from gravity pulling the ball down). One subtlety is that the pressure acts on each little part of the surface in a normal direction (each little tiny force vector points toward the center of the ball). So if you understand how to integrate vectors along a surface, you see that all the horizontal components cancel out, and you are left just with the vertical component balancing the weight. If you haven't learned how to integrate vectors over a surface yet, don't worry about it. That's why I said in a previous post to use the diameter of the ring in your area calculation of the required pressure. Then:

F = weight = mass of ball * acceleration of gravity = m * 9.8m/s^2

F = water pressure * area of ring

Set the two equal to determine the water pressure required to balance the ball. A little excess pressure lifts it enough for a little water to spill out of the seal around the ring, and presto. Disneyland!

Oh, and be careful to check your units in those calculations. m/s^2 is not directly compatible with PSI, for example. You need to do the appropriate unit conversions.

## 1. What is a ball fountain?

A ball fountain is a type of water feature that consists of a vertical tube or pipe with multiple balls placed inside. The balls are typically made of a lightweight material, such as plastic, and are arranged in a stack with a small gap between them. Water is pumped up through the bottom of the tube and flows out through the gaps between the balls, creating a mesmerizing visual effect.

## 2. How does a ball fountain work?

A ball fountain works through the principles of equilibrium and water force. When water is pumped up through the tube, it exerts pressure on the balls, causing them to rise up and create a gap for the water to flow out. This process continues as long as the pump is running, creating a constant stream of water through the fountain.

## 3. What is the role of equilibrium in ball fountain physics?

Equilibrium is a state in which opposing forces are balanced. In a ball fountain, the upward force of the water pressure is balanced by the downward force of gravity on the balls. This balance of forces allows the balls to remain suspended in the vertical tube, creating the unique visual effect of the fountain.

## 4. How does water force affect a ball fountain?

Water force refers to the force exerted by the flowing water in the fountain. In a ball fountain, the force of the water is what causes the balls to rise up and create a gap for the water to flow out. The strength of the water force is determined by the speed and volume of the water being pumped through the fountain.

## 5. Are there any practical applications for understanding ball fountain physics?

While ball fountains are primarily used for decorative purposes, understanding the physics behind them can have practical applications. This knowledge can be applied in the design and construction of other water features, such as fountains and waterfalls. It can also be useful in engineering and fluid dynamics, as well as in educational settings to teach principles of equilibrium and water force.

• Mechanics
Replies
14
Views
2K
• Mechanics
Replies
1
Views
1K
• Mechanics
Replies
1
Views
980
• Mechanics
Replies
6
Views
806
• Mechanics
Replies
25
Views
3K
• Mechanics
Replies
1
Views
1K
• Mechanics
Replies
10
Views
6K
• Mechanics
Replies
8
Views
2K
• DIY Projects
Replies
7
Views
737
• Mechanics
Replies
11
Views
5K