Problem related to Milikan's Oil Drop Experiment

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To determine the weight of the suspended oil drop in Millikan's Oil Drop Experiment, the relevant formulas include potential energy (PEe = -qEd), voltage (V = W/q), and capacitance (C = q/V). The charge of the oil drop is given as 8 x 10^-19 C, and the potential difference between the plates is 1200 V with a separation of 8 mm. The weight of the oil drop can be inferred by balancing the electric force against gravitational force, indicating that the charge must correspond to multiple electrons. To calculate the weight, the mass of a single electron is needed, which is approximately 9.11 x 10^-31 kg. Understanding the forces acting on the droplet and ensuring it is in equilibrium is crucial for solving the problem.
NYROCKFAN
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How would I figure out the answer to this question (what formulas)?

Here are the formulas I've been using for this homework assignment:
PEe = -qEd
V = W/q
V = -Ed
C = q/V

Question:
An oil drop having a charge of 8 x 10^-19 C is suspended between two charged parallel plates. The plates are separated by a distance of 8 mm, and there is a potential difference of 1200 V between the plates. What is the weight of the suspended oil drop?
 
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By the way... this assigment is being collected & graded.
 
wait a minute... I think I have it. I just need the weight of one electron (in kg). Anyone know that?
 
OOps... I meant mass in kg or weight in Newtons.
 
The oil drop experiment doesn't measure the mass of an electron. It measures the charge of an electron.

The idea is that if you can measure how big the oil droplet is, you can figure out its weight. If it's floating, then the charge is balancing the weight.

The charge might be any number of electrons though: 1, 2, 3, etc.

So you have to look for the drops that float, but only just - the ones that float easily with a low voltage on the plates have two or more spare electrons on them.
 
Ask yourself what forces are acting on this droplet? Since the droplet isn't moving, what can you say about these forces? Draw a diagram if need be.
 

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