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Dissipation of Power by Resistors

  • Thread starter cwesto
  • Start date
  • #1
18
0

Homework Statement



untitled.jpg


Homework Equations



P=IV
I=V/R
P=(V/R)V
R=V2/R

The Attempt at a Solution



PR1: 122/12=12
PR2: 144/18

I'm not sure what to do from here. Thanks for any input and help!
 

Answers and Replies

  • #2
LowlyPion
Homework Helper
3,090
4
Maybe start with how much current is passing through the resistors?

Your attempt incorrectly tried to use the total Voltage of the supply across the resistors singly. The question wants to know the power dissipated by each resistor.

Once you have the current then won't the power for any resistor be P = I2R ?
 
  • #3
18
0
I=V/R
Rtotal=12+18
I=12/30
PR1=RI2
PR1=12*[tex]\frac{2}{5}[/tex]*[tex]\frac{2}{5}[/tex]
PR1=48/25

PR2=[tex]\frac{72}{25}[/tex]=2.88
Thanks!
 
  • #4
LowlyPion
Homework Helper
3,090
4
I=V/R
Rtotal=12+18
I=12/30
PR1=RI2
PR1=12*[tex]\frac{2}{5}[/tex]*[tex]\frac{2}{5}[/tex]
PR1=48/25

PR2=[tex]\frac{72}{25}[/tex]=2.88
Thanks!
There you go. Good job.
 

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