What the isn't this plug and chug?

  • Thread starter mr_coffee
  • Start date
In summary, a car battery with a 12 V emf and an internal resistance of 0.050 is being charged with a current of 60 A. The potential difference across its terminals (V) can be found using the equation V = EMF - ir, where r is the internal resistance and i is the current. However, since the battery is being charged, the resulting voltage should be higher than the nominal voltage. The formula used for discharging a battery may need a simple change in sign to be applicable for charging.
  • #1
mr_coffee
1,629
1
A car battery with a 12 V emf and an internal resistance of 0.050 is being charged with a current of 60 A.

(a) What is the potential difference V across its terminals?

Okay i have an equation that should work perfectly!
Points a and b are located at he terminals of the battery, thus the potential difference Vb-Va is the termian to terminal potential difference V across the battery, we see that:
V = EMF - ir. r is the internal resitance of the battery, and they give me 60 amps as the current?
V = (12V)-(60A)(.050) = 9V, which is wrong!
 
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  • #2
You are CHARGING the battery, not discharging the battery, so there is no way the resulting voltage would be lower than the nominal voltage...
 
  • #3
I looked in the book and it gives me no case if ur charging the battery, what's the difference? It also didn't say that the formula i used is only for discharging a battery
 
  • #4
A simple change in sign of the term "ir" maybe??
 
  • #5
Ohhh! thanks again bigman! :biggrin:
 

What is "plug and chug" in science?

"Plug and chug" refers to the practice of blindly plugging numbers into equations without understanding the underlying concepts or logic behind them. This approach often leads to incorrect results and a lack of true understanding of the scientific principles being studied.

Why is "plug and chug" not a good scientific method?

"Plug and chug" is not a good scientific method because it relies solely on memorization and does not encourage critical thinking or problem-solving skills. It also does not allow for a deeper understanding of the principles being studied.

What are some alternatives to "plug and chug" in science?

Some alternatives to "plug and chug" in science include using problem-solving strategies, such as breaking down a problem into smaller parts, applying previous knowledge, and using logical reasoning. It is also important to have a good understanding of the underlying concepts and to ask questions to deepen understanding.

How can "plug and chug" lead to incorrect results?

Since "plug and chug" involves blindly plugging in numbers without understanding the underlying principles, it can lead to incorrect results if the numbers used are incorrect or if the equation is being applied incorrectly. This approach does not allow for critical thinking or double-checking of results.

How can I avoid relying on "plug and chug" in my scientific studies?

To avoid relying on "plug and chug" in scientific studies, it is important to focus on understanding the underlying principles and concepts being studied. This may involve asking questions, seeking clarification, and practicing problem-solving strategies. It is also beneficial to review and reflect on previous lessons and to actively engage in the learning process rather than just memorizing equations and formulas.

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