Will the water rise in a capillary when placed on a freely falling lift?

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Homework Help Overview

The discussion revolves around the behavior of water in a capillary tube when the tube is placed in a water vessel inside a freely falling lift. Participants are exploring the implications of free fall on capillarity and surface tension.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants are considering the effects of free fall on the forces acting on the water, particularly how gravity's absence might influence the rise of water in the capillary. There is a debate on whether the water will rise or remain at a certain level, with references to surface tension and molecular forces.

Discussion Status

Multiple interpretations are being explored regarding the behavior of water in the capillary under free fall conditions. Some participants suggest that surface tension remains effective, while others question the role of weight in this scenario. No consensus has been reached yet.

Contextual Notes

Participants are grappling with the implications of free fall on the physical properties of water and the assumptions about surface tension and weight in this context.

sowmya2010

Homework Statement



A capillary is dipped in water vessel kept on a freely falling lift, then

a)water will not rise in the tube
b)water will rise to the maximum possible height of the tube

Homework Equations



W=2\pir S cos\theta
or h=(2S cos \theta)/(r\rhog)

The Attempt at a Solution



as this is the case of free fall g tends to 0 hence h tends to infinity hence the option (b)

but it might also mean that cos \theta=0, i.e, the water doesn't rise at all, hence the option (a)

which logic is correct?
 
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Just an educated guess here, as no one else is around--but the way I see it the tendency to minimize surface area and hence form some angle theta is a function of surface tension which is independent of weight. The capillarity (attraction to the glass and consequent pull up the side is also present. OTOH, what happens to the weight of the water as it free falls?
 
Last edited:
I'm guessing here too, but I'd imagine it'd rise to the top of the tube, as the molecular forces responsible for the surface tension are still present, but the water has no effective weight as the lift is in free fall, therefore there will be a net upward force which will pull the water up the tube.
 
And on outer surface as well, I think
 

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