A small sphere with mass m carries a positive charge q and
Chapter 21, Problem 21.84(choose chapter or problem)
A small sphere with mass m carries a positive charge q and is attached to one end of a silk fiber of length L. The other end of the fiber is attached to a large vertical insulating sheet that has a positive surface charge density s. Show that when the sphere is in equilibrium, the fiber makes an angle equal to arctan 1qs>2mgP02 with the vertical sheet.
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