Calculate Charge from Mass, Potential Difference & Distance

AI Thread Summary
To calculate the charge of an oil drop with a mass of 3.6 x 10^-12 kg in a potential difference of 250.4 V across parallel plates 0.41 cm apart, the relevant formula is q = (Vr)/k, where k is Coulomb's constant (9.0 x 10^9 N m²/C²). The electric field strength between the plates is crucial for understanding the forces acting on the droplet, which is assumed to be stationary. The initial calculation yields a charge of approximately 1.1 x 10^-10 C, but clarification on the role of mass and the setup is needed for accuracy. The discussion emphasizes the importance of context in physics problems to ensure proper understanding and solution. Understanding the forces acting on the droplet is essential for a complete analysis.
wow22
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Homework Statement

Find the charge
find the charge:
mass : 3.6*10^-12 kg
electric potential difference: 250.4 V
parallel plates are 0.41 cm apart

PLEASE DO NOT link me a wikipedia page.. or give me a one sentance explanation of something unrelated to this question
Just need to know how to find charge in this case
Thanks for the help in advance!

Homework Equations


I thought it was:
V=(kq)/r
so q= (Vr)/k
But what would the mass be there for?

The Attempt at a Solution


q= (Vr)/k
q= (250.4*0.0041m)/(9.0*10^9)
q=1.1*10^-10

i don't know whether this is the right way of finding it
 
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wow22, I think you have abbreviated the details too much, and what you provided is not meaningful. Parallel plates I understand, voltage across the plates I understand. But mass...? What body is this whose mass is part of the question? And what is it is that has a radius?
 
It's the mass of an oil drop and I am looking for the charge of it. That's basically all the info given to me, and the question isn't really given to me in a word question, it just says to find the charge of the drop with info in chart provided.
 
wow22 said:
It's the mass of an oil drop and I am looking for the charge of it. That's basically all the info given to me, and the question isn't really given to me in a word question, it just says to find the charge of the drop with info in chart provided.

Why didn't you explain the setup in your first post? Without context your question is indecipherable.

What is the electric field strength between the plates?
What forces are acting on the charged droplet?
 
not sure ..
considering it didn't say I'm going to assume that it's stationary.
 
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