Question

Two metallic spheres of mass .001 kg hang from a point by .3 m strings. Each is given the same amount and sign of charge. After equilibrium is reached, they each make an angle of 20 degrees relative to the vertical. Determine the amount of charge in each sphere.

Answer 1

Before we start the distance between the balls is .205m
Tension in string
Tcos20 = mg
so T = mg/cos20
Solve for T
Tsin20 = kq^2/r which we found from geometry.
Solve for q
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