Capillary Tube Behavior in a Gravityless Environment

In summary, the question is about the length of a water column in a capillary tube when placed in a freely falling elevator. The correct answer is 20 cm, as during free fall there are no forces to stop the water from rising and it will occupy the full capillary tube due to adhesion.
  • #1
Navin
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Homework Statement


A 20 cm long capillary tube is dipled in water.The water rises up to 8cm .if the entire arrangement is put in a freely falling elevator ,the length of the water column is

A)10cm

B)8cm

C)20cm

D)4cm

Homework Equations


Its a theoretical sum

The Attempt at a Solution


Okay...since this is a freely falling elevator ,the reletive accelaration will be zero and hence i feel the fluid will maintain its orignal height of 8cm

But alas ,the book says its 20cm and have give the reason that since its "gravityless" ie :rel accelaration 0, it will occupy full capillary tube.

[Edit 1 -fixed a typo
Edit 2 - i wrote about what i did in Edit 1]
 
Last edited:
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  • #2
What are the forces acting on the column of water in the capillary before you put it in the elevator? What force is pulling the water up the capillary against gravity?
 
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  • #3
Chandra Prayaga said:
What are the forces acting on the column of water in the capillary before you put it in the elevator? What force is pulling the water up the capillary against gravity?

Oh ! I think i got it !
Case 1
Alright ,so before we put the fluid in the elevator we have forces of adhesion pulling water up the capillary tube,but one it reaches a certain hieght ,force of gravity dominates and hence it can't go further

Case 2
During free fall there is nothing to stop the liquid from rising ,that is ,due to adhesion the liquid continues to rise until it occupies full cappilary tube !
 
  • #4
Hence the answer should be 20 cm right ?
 

What is a "Gravityless" Capillary Tube?

A "Gravityless" Capillary Tube is a tube that utilizes capillary action to move liquid without the influence of gravity. It is often used in microfluidic devices and experiments that require precise control of liquid movement.

How does a "Gravityless" Capillary Tube work?

A "Gravityless" Capillary Tube works by utilizing the properties of surface tension and adhesion. The liquid is pulled up the tube due to the attraction between the liquid molecules and the inner surface of the tube.

What are the benefits of using a "Gravityless" Capillary Tube?

The use of a "Gravityless" Capillary Tube allows for precise control of liquid movement and eliminates the influence of gravity. This is especially useful in experiments that require precise measurements or in microfluidic devices where gravity may interfere with liquid flow.

What types of liquids can be used in a "Gravityless" Capillary Tube?

Most liquids can be used in a "Gravityless" Capillary Tube, as long as they have surface tension and can be pulled up the tube. However, the tube material and dimensions may need to be adjusted for different types of liquids.

Are there any limitations to using a "Gravityless" Capillary Tube?

One limitation of using a "Gravityless" Capillary Tube is that the tube must be kept in a horizontal position to maintain the absence of gravity. Additionally, the tube material and dimensions must be carefully chosen to ensure successful capillary action.

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