Calculating Q (dot): William Needs Help

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SUMMARY

The discussion centers on the calculation of power (Q dot) using the formula Q(dot) = V * A, where V represents voltage and A represents current. Participants clarify that power is measured in watts, which can be expressed in various units including joules per second (J/s) and Newton-meters per second (Nm/s). The equivalence of these units is established through the relationship between voltage, current, and power, confirming that V * A indeed results in watts. This understanding resolves William's inquiry regarding the units associated with the calculation.

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skaboy607
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Hi

Wondering if someone could help me satisfy my curiosity. Hopefully a very simple for someone who knows. I have been given values for Voltage and Current. To calculate Q (dot), I know Q(dot)=V * A. The units for this are Watts / J/s / Nm/s.. How can Voltage multiplied by a current provide these units?

Thanks

William
 
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Welcome to PF!

Hi William! Welcome to PF! :smile:

From electric units in the PF Library

Power = voltage.current = energy/time (dim. ML^2/T^3):

\text{W}\ \equiv\ \text{watt}\ \equiv\ \frac{\text{J}}{\text{s}}\ \equiv\ \frac{\text{joule}}{\text{second}}\ \equiv\ \frac{\text{N.m}}{\text{s}}\ \equiv\ \frac{\text{Newton.metre}}{\text{second}}\ \equiv\ \text{V.A}\ \equiv\ \text{volt.amp}\ \equiv\ \Omega\text{.A}^2\ \equiv\ \text{ohm.amp}^2
 
Thank you very much. Good to of joined.

Thats that sorted then, thanks for clearing up.

William
 

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