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Two Styrofoam balls with the same mass m = 9.00 × 10−8 kg and the same positive charge Q are suspended from the same point by insulating threads of length L = 0.705 m. The separation of the balls is d = 0.0221 m. What is the charge Q?

User ScottA
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1 Answer

4 votes

Answer:


q = 3.87 * 10^(-11) C

Step-by-step explanation:

As we know that the two styrofoam balls are suspended in equilibrium

so we will have


Tcos\theta = mg


Tsin\theta = (kqq)/(d^2)

also we know that


sin\theta = (d)/(2L)


sin\theta = (0.0221)/(2(0.705))


\theta = sin^(-1)(0.0313) = 1.79 degree

so we will have

now from above two equations we have


tan\theta = (kq^2)/(mgd^2)


tan(1.79) = ((9* 10^9)q^2)/((9* 10^(-8))(9.81)(0.0221)^2)


q = 3.87 * 10^(-11) C