- #1
Soniteflash
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Homework Statement
Two small plastic balls hang from threads of negligible mass. Each ball has a mass of
0.14 g and a charge of magnitude q. The balls are attracted to each other and the threads attached to the balls make an angle of 20.0 degree. with the vertical. The balls are 2.05 cm apart.
A. Find the magnitude of the electric fore acting on each ball
B. The tension in each of the threads
C The magnitude of the charge of the charge on the balls.
Homework Equations
The Attempt at a Solution
A. Since they attract each other. there has to be an attraction force between the two charges.
I assumed that there is a force that acts against it in the horizontal direction. The cable has tension so I thought that the x-component of the force has to act against the attraction force. With that in mind I needed to find out the x-component of the tension, FT which would then equal the magnitude of the electric force.
I am not sure if my thought process is right. I am also confused on how to calculate the the x component of the tension. Would it be: ∑Fx = FTx= mg sin(20) = ma (which is zero since it doesn't move) ?
Since I couldn't figure out A, I was reluctant to continue.