Calculating Angle for Water Rolling on Glass Plane

AI Thread Summary
To determine the angle at which water droplets begin to roll down a glass plane, one must consider the effects of surface tension, which is influenced by the glass surface's smoothness, type, and any impurities present. The calculation is not straightforward, as there is no universal angle for all glass types due to varying surface properties. Experimentation is suggested for precise results, but a rough calculation can be derived from understanding these parameters. Factors such as surface charge and the presence of detergents play a significant role in altering surface tension. Ultimately, the project requires a balance of theoretical calculations and practical experimentation to achieve the desired angle for optimal water flow.
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Homework Statement


So I need to get a rough calculation:
At what angle does drops of water start rolling down a plane of glalss.
This is for my project where we are using a solar still to purify water. I just need ot get a rough calculation so I know at what angle to tilt the plane of glass. I am aware that I could experiment but for the class I need calculations.
Thanks.
 
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Surface tension is what is stopping the drops from moving.
You will need to investigate what parameters effect the surface tension - this is going to be dominated by the nature of the glass surfacd, how smooth, what type of glass (surface charge) and any impurities on the surface ( particulalry detergents).

There isn't a single number for just glass.
 
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