Prove Voltage should be linear function of position

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Homework Help Overview

The discussion revolves around the relationship between voltage and position in a wire, specifically examining whether voltage can be expressed as a linear function of distance along the wire. The original poster presents a formula for voltage, V(x), and seeks to express it in terms of wire length, battery voltage, and constants.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the expression of voltage in terms of wire length and constants, with some questioning the need for a specific numerical value for the slope. Others express confusion about the phrasing of the problem and the implications of being "given" a linear function.

Discussion Status

The conversation is ongoing, with participants exploring different interpretations of the problem. Some have provided insights into the relationship between voltage and length, while others are questioning the assumptions behind the original poster's approach. There is no explicit consensus, but various lines of reasoning are being examined.

Contextual Notes

Participants note that the problem is part of a physics lab, suggesting that experimental data may be involved. There is also mention of a specific slope value derived from a graph, which may influence the discussion on how to express voltage in relation to distance.

avs
Giving that: V(x)=Cx
Express the answer in terms of wire length L, battery voltage Vin the variable x and any numerical or physical constant. C should equal to 1.3594 which is the slope of my volage vs distance graph.

This is what i got so far. Not sure if it is correct.
V=iR -> V=(i*(rho)*L)/A so therefore my C is i(rho)/A and L=x

Am i going in the right direction?
 
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Well, obviously C = Vin/L.
So V(x) = Vin*x/L.
I can't see what for you need the numerical value, or a graph.
Is this really college level?
 
Last edited:
yea it's for a physics 2 lab.
 
I'm puzzled by your titling this "Prove Voltage should be linear function of position" and then imediately saying "Giving (Given?)that: V(x)=Cx"

If the problem is to prove something, then you wouldn't be "given" it!

Since this is for a physics LAB, I suspect that you were asked to measure voltage versus length of wire in the laboratory, then graph the data. "Proving" (not in the mathematical sense) that voltage is a linear function of length is just a matter of observing that the points tend to lie along a line.

Since you say that you have already done that and found that the slope of the line is 1.3594, you know that you can write V(x) as
V(x)= 1.3594x+ V0 (V0 is the voltage when x= 0. If I understand your experiment correctly, that should be Vin.)

You are asked to "Express the answer in terms of wire length L, battery voltage Vin the variable x and any numerical or physical constant."

Okay, what is the voltage when x= L, then entire length of the wire?
If you call that Vl, then you should have (Vl- Vin)/L= slope= 1.3594.
 

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