What is the power output in kW for this measurement?

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In summary, to calculate power using a watt-hour meter, you can use the formula: power = (3600 seconds per hour) / (time for 10 revolutions) * (10 revolutions / 400 revolutions) * 1 kWh. This will give you the power in kilowatts (kW). Alternatively, you can also use the formula: power = (1 kWh) / (400 revolutions) * (10 revolutions / time in seconds) * 3600 seconds per hour. Both formulas should give you the same result, with the power being measured in kilowatts (kW).
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Inquiring_Mike
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Homework Statement


We used a watt-hour meter in a lab, 400 revolutions of the dial = 1kWh. We measured the time for 10 revolutions of the dial ( in seconds).
How would I calculate the power?

Time for 10 revs = 146s

Homework Equations


The Attempt at a Solution


Power = (3600s/hr) / (146s) * (10/400) *1kWh = 0.62069 W ?
 
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  • #2
Does one mean Time for 10 revs = 146s or 146 revs in 10 s?
 
  • #3
Sorry... fixed :)
 
  • #4
... After some more thinking...I think it should be 0.62069 kW. Would this be correct?
 
  • #5
Any help would be very much appreciated... :)
 
  • #6
Inquiring_Mike said:
... After some more thinking...I think it should be 0.62069 kW. Would this be correct?

Yes, but I calculate 0.6164 kW.

Take (1 kWh)/(400 revs)*(10 revs/ 146 s) * 3600 s/h = ______ kW.

The unit kWh is simply power (kW) * time (hours) = energy. 1 kW-s = 1 kJ, so 1 kWh = 3600 kJ.
 

FAQ: What is the power output in kW for this measurement?

1. How do I calculate the power using electrical current and voltage?

To calculate power, you can use the formula P = I x V, where P is power in watts, I is current in amperes, and V is voltage in volts. Simply multiply the two values together to get the power.

2. Can power be calculated using other units besides watts, amperes, and volts?

Yes, depending on the given values, power can also be calculated using other units such as joules, kilowatts, or horsepower. You may need to use conversion factors or different equations to calculate power in these units.

3. How do I calculate the power of a mechanical system?

To calculate the power of a mechanical system, you can use the formula P = F x d/t, where P is power in watts, F is force in newtons, d is distance in meters, and t is time in seconds. This formula takes into account the amount of work done over a certain distance and time.

4. Is there a difference between instantaneous power and average power?

Yes, instantaneous power refers to the power at a specific moment in time, while average power is the average of the power over a period of time. To calculate average power, you can use the formula P = W/t, where P is power in watts, W is work in joules, and t is time in seconds.

5. How do I calculate the power of a light source?

To calculate the power of a light source, you can use the formula P = I x A, where P is power in watts, I is intensity in candela, and A is the area of the light source in square meters. This formula takes into account the brightness and spread of the light source.

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