Calculating Power Dissipation in a Simple Circuit

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Homework Help Overview

The discussion revolves around calculating power dissipation in a simple circuit involving two resistors (R1 and R2) and a voltage source. Participants are attempting to understand the relationships between voltage, current, and power in this context.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants are exploring different formulas for power dissipation, questioning whether to combine resistances, and discussing the implications of negative power values. There are attempts to clarify the definitions of initial and final voltage in the context of power calculations.

Discussion Status

The discussion includes various interpretations of power dissipation and the relationships between voltage, current, and resistance. Some participants have provided guidance on using specific formulas, while others express confusion about certain concepts, such as voltage drops and the meaning of initial and final values.

Contextual Notes

There are indications of missing information regarding the circuit setup, and participants are grappling with the implications of their calculations, particularly in relation to negative values for power dissipation.

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Homework Statement


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How much power is dissipated by R1? (R1=8 Ω, R2=17 Ω, V=6 V.)

Sorry the picture is so big!

Homework Equations





The Attempt at a Solution



P = E^2/R = 8^2/6 = 10.67W what am I doing wrong?
 
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Do I have to add the resistors??
 
No P=IV so the change in power is the dissipation of power so delta P=IV-IV
so use v=IR and get P=I^2R -I^2R for the points after and at (before) the resistor, also remember always final-initial
 
So I would do...
I = E/Req = 6/25
P = 0.24^2 * 8 - 0.24^2 * 17 = -0.5184
Negative? Why would it be negative?
 
Can someone explain this...

No P=IV so the change in power is the dissipation of power so delta P=IV-IV
so use v=IR and get P=I^2R -I^2R for the points after and at (before) the resistor, also remember always final-initial

I don't understand what Vi and Vf are?
 
so i need to multiply the voltage drop across the resistors by the current. but how do i calculate the voltage drop?
 
solved...
 

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