Electric Potential: Calculating Energy & Power

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Homework Help Overview

The problem involves calculating the energy wasted and power consumed by a toaster when a specific charge flows through it over a given time. The subject area includes concepts of electric potential, energy, and power in electrical circuits.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the relationship between charge, voltage, energy, and power, referencing formulas such as work = qv and power = work/time. Some participants express uncertainty about their calculations and seek clarification on the formulas used.

Discussion Status

The discussion is active, with participants exploring different approaches to the problem. Some guidance has been offered regarding the use of formulas and units, but there is no explicit consensus on the correctness of the calculations presented.

Contextual Notes

Participants are working under the constraints of a homework assignment, which may limit the information they can use or the methods they can apply. There is an emphasis on understanding the relationships between charge, energy, and power without providing direct solutions.

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Homework Statement



how much energy is wasted when 35 C of charge flow through a 120 V toaster in 5.0 S?
how much power?

Homework Equations


work=qv i think...

power= work /time

The Attempt at a Solution



i thought to find energy wasted i would find the work used. (?yes?)

so i guess that would be 35(120) whihc is 4200 J


so then do i power = 4200/5=840


is this correct?
 
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well P = IV

and they give you the time...so you know the units of Power = (Joules/second), so given the time you can find the joules wasted...

both problems solved with one equation!

:D
 
wait i didnt really understand what u just said.
did i do this right or is it wrong?
 
no recheck your work and look at the formula I gave you and the units of power, energy is in JOULES, and power is in Watts or Joules/second...it should be straightforward from there
 
well a watt = J/sec
so i got energy in joules correct right??

then those Joules per 5 sec gives u 840 J/ a sec
 
ok another formula that will help is to know that I (current) is equal to (change in Q- the charge)/ (change in time - seconds), both of these informations are given in the problem...

once you find I...you can solve for P = IV, using the information given in the problem...
 
oh and I forget to mention that the change in potential difference (V) is equal to the potential-energy change per unit charge in moving across the toaster...so U = Vq...you know volts and know q so you can find the energy lost.
 
so isn't i=7
and then 7(120)=840...
 
ddint i do that in the proble, above?
 
  • #10
ohh..lol my bad, yes your work is correct, sorry for the explanation again above...wasn't thinking so simply...
 

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