Archimedes principle with a completely submerged ball

In summary, the conversation discusses the principles of buoyancy and pressure in relation to a ball submerged in water. The speaker questions whether a ball completely submerged will remain underwater due to the pressure exerted by the water column above it. The other party argues that the pressure is actually higher at the bottom of the ball and explains the concept of upthrust. They then discuss the possibility of a ball remaining submerged if no water slips in, but note that it is difficult to achieve.
  • #1
dasky
2
0
Greetings,
I have a question about the classic Archimede's principle.
A ball inflated with air will not sink into water. My understanding is that it will be pushed from all directions by the surrounding water trying to fill the space occupied by the ball. So there will be a pressure downwards formed by the water column above the ball, and there will be pressure upwards from the water below the ball, and obviously on the sides.
My question is: if a ball is completely submerged there will be a lot of pressure downwards but no or very little pressure upwards, will the ball remain submerged?
Thanks
Dasky
 
Physics news on Phys.org
  • #2
dasky said:
My question is: if a ball is completely submerged there will be a lot of pressure downwards but no or very little pressure upwards,
No, your premise is wrong. The pressure is higher at the bottom of the ball (it is deeper and pressure grows linearly with depth).
 
  • #3
Then what about a different container, like a box, resting on the bottom of a pool? the face in contact with the surface of the pool will have no water pushing upwards, so will it remain down?
 
  • #4
dasky said:
Greetings,
I have a question about the classic Archimede's principle.
A ball inflated with air will not sink into water. My understanding is that it will be pushed from all directions by the surrounding water trying to fill the space occupied by the ball. So there will be a pressure downwards formed by the water column above the ball, and there will be pressure upwards from the water below the ball, and obviously on the sides.
My question is: if a ball is completely submerged there will be a lot of pressure downwards but no or very little pressure upwards, will the ball remain submerged?
Thanks
Dasky
The pressure under the ball will be greater because it is deeper.
By the way, I have noticed that if such a ball is pushed down under water and then released, the upward acceleration cannot exceed -g. This is because water has to fall by gravity into the space vacated in order to create the upthrust.
 
  • #5
dasky said:
Then what about a different container, like a box, resting on the bottom of a pool? the face in contact with the surface of the pool will have no water pushing upwards, so will it remain down?

If you can arrange it such that really no water slips in. This is difficult, but a priori possible.
 

1. What is Archimedes principle?

Archimedes principle states that any object completely or partially submerged in a fluid will experience an upward buoyant force equal to the weight of the fluid it displaces.

2. How does Archimedes principle apply to a completely submerged ball?

When a ball is completely submerged in a fluid, it will experience an upward buoyant force equal to the weight of the fluid it displaces. This force acts in the opposite direction of gravity, resulting in a net upward force on the ball.

3. What factors affect the buoyant force on a completely submerged ball?

The buoyant force on a completely submerged ball is affected by the density of the fluid, the volume of the ball, and the acceleration due to gravity.

4. How can Archimedes principle be used to calculate the buoyant force on a completely submerged ball?

To calculate the buoyant force on a completely submerged ball, you can use the formula Fb = ρVg, where ρ is the density of the fluid, V is the volume of the ball, and g is the acceleration due to gravity.

5. What are some real-world applications of Archimedes principle with a completely submerged ball?

Archimedes principle with a completely submerged ball has many practical applications, such as determining the weight of an object by measuring its buoyant force, designing ships and submarines, and understanding the behavior of objects in fluids.

Similar threads

I A specific case of an exception to Archimedes' Principle?
    • Mechanics
2
Replies
40
Views
2K
Buoyancy and the Archimedes Principle
    • Introductory Physics Homework Help
Replies
6
Views
1K
General Query on Archimedes' Principle
    • Introductory Physics Homework Help
Replies
14
Views
4K
MHB Physics - Archimedes principle
    • General Math
Replies
3
Views
801
"Air Pressure" is not "the weight of the air above you"
    • Mechanics
Replies
27
Views
2K
I Filling a pool with the hose end above or in the water
    • Classical Physics
Replies
10
Views
256
Find Time to Reach Top of Beaker (10 cm)
    • Introductory Physics Homework Help
Replies
16
Views
1K
Falling Feather and ball in vacuum
    • Mechanics
Replies
13
Views
1K
Minimum gas pressure to measure its volume with an eudiometer
    • Mechanics
Replies
1
Views
1K
Buouyancy force and Archimedes' principle
    • Introductory Physics Homework Help
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top