# Power and Temperature

1. Aug 17, 2011

### math111

can someone explain how power relates to temperature???

I now understand that a 100W lightbulb over 1 hour will be 100W-Hr

WRONG:
100W in 1 Hr = Light bulb@100Watts
100W in 2 Hr = Light bulb@200Watts
....

RIGHT
100W in 1 Hr = Light bulb 100Watts-Hr used
100W in 2 Hr = Light bulb 200Watts-Hr used

So is there such thing if I am using 100W for 1 Hr in that hour is there an average temperature rise that will occur to be using 100W each hour for lets say 5 hours and end up using 500W-Hr with a 100W/Hr Temperature???

2. Aug 17, 2011

### Drakkith

Staff Emeritus
Temperature is not measured in watts, so I am unsure of what you want to know. The power use of a lightbulb relates to the amount of current through it.(Since voltage applied is constant) By varying the resistance and material you can make light bulbs with more or less wattage. Since current is what causes the filament to heat up, more current = higher temp, which means more light for a conventional light bulb.

3. Aug 17, 2011

### Staff: Mentor

A light bulb heats up to its operating temperature in seconds, then stays at a steady temperature, with the input electrical energy equaling the output heat and light energy.