Calculating Potential Difference in a Suspended Parallel Plate Capacitor

AI Thread Summary
To calculate the potential difference in a suspended parallel plate capacitor, the mass of the object, its charge, and the angle of the thread with the vertical are crucial. The mass of 420 mg and charge of 30.0 nC are given, with the plates separated by 2.00 cm and the thread at an 18.0° angle. The horizontal force acting on the mass due to the electric field can be determined by analyzing the forces involved. Using the equation for potential energy and the relationship between force and potential difference, the potential difference can be calculated. Understanding the role of mass and angle is essential for solving the problem accurately.
kkevinzhang
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Homework Statement



A small object with a mass of 420 mg carries a charge of 30.0 nC and is suspended by a thread between the vertical plates of a parallel-plate capacitor. The plates are separated by 2.00 cm. If the thread makes an angle of 18.0° with the vertical, what is the potential difference between the plates?

Mass: 420 mg
Charge: 30.0 nC
Distance between plates: 2.00 cm
Thread of object: 18.0 degrees from vertical

Homework Equations



PE = -q(Vb-Va)
V = kq/r


The Attempt at a Solution



I just don't understand how the mass in the middle and the angle affects the problem.
 
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welcome to pf!

hi kkevinzhang! welcome to pf! :smile:
kkevinzhang said:
I just don't understand how the mass in the middle and the angle affects the problem.

draw a https://www.physicsforums.com/library.php?do=view_item&itemid=100" to find the horizontal force on the mass …

then calculate the potential difference which would produce that force :wink:
 
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thanks!
 

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