Conversion units mystery. Am I wrong?

In summary, the potential difference between two points is 140mV and 280μJ of work are required to move a charge Q from one point to the other. Using the equation Q = W/V, we can convert the units to J and C and solve for Q. The result can then be converted to any desired units.
  • #1
giraffeinaboat
1
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Homework Statement


The potential difference between two points is 140mV. If 280μJ of work are required to move a charge Q from one point to the other, what is Q?

Homework Equations


Q = W/V

The Attempt at a Solution


http://imgur.com/FDaQfb9
 
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  • #2
Hi, welcome to PF!

Convert the potential difference to volts, and the work to joules. Dividing joules with volts, you get coulombs for the charge. mJ/mV is also coulomb.

ehild
 
  • #3
You are assuming that mJ divided by mV gives mC. That's wrong, it gives C. In general, you have overcomplicated things too much. Just convert everything into J and C, compute the result, then convert it to any units you want.
 

FAQ: Conversion units mystery. Am I wrong?

What is the "Conversion units mystery"?

The Conversion units mystery refers to the confusion and uncertainty that arises when converting between different units of measurement, such as from metric to imperial or vice versa.

Why is converting units important?

Converting units is important for accurate and consistent measurement. It allows us to compare and communicate measurements across different systems and to make calculations more precise.

What are the most common conversion units that people struggle with?

The most common conversion units that people struggle with are those related to length (meters, feet, inches), weight (kilograms, pounds, ounces), and temperature (Celsius, Fahrenheit).

How can I avoid making mistakes when converting units?

The best way to avoid mistakes when converting units is to use unit conversion tables or calculators, and to double check your calculations. It is also important to understand the relationships between different units and to be familiar with conversion factors.

Is there a standard method for converting units?

Yes, there is a standard method for converting units called the factor-label method or dimensional analysis. This involves setting up a conversion factor and cancelling out units to arrive at the desired unit of measurement.

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