Thursday
July 31, 2014

Homework Help: physics....again

Posted by april on Saturday, January 31, 2009 at 12:14pm.

A typical light bulb is 2% efficient. It means that only 2% of electric energy is converted into visible electromagnetic radiation and 98% is converted into ultraviolet radiation known as heat. Suppose a 100W bulb is turned on for 10h.

a. how much energy is used by the lamp? express in kWh.

b. how much energy is wasted due to heat?

c. suppose that the light bulb is turned on for a longer period of time. would you expect its efficiency to increase or decrease?

Please help me...i was absent from class the day we learned this...

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

chemistry - Infrared, ultraviolet, and visible radiation are all part of the ...
Chemistry Lab - Infrared, ultraviolet, and visible radiation are all part of the...
Physics - We can reasonably model a 75 W incandescent light bulb as a sphere 6....
Science - Does infrared radiation or ultraviolet radiation have wavelengths that...
science - In the process called fluorescence, some substances absorb photons of ...
CHEM URGENT - Infrared, ultraviolet, and visible radiation are all part of the ...
Physics - We can reasonaly model a 75 W incandescent lightbulb as a sphere 6 cm ...
Physics - When a positive charge moves in the direction of the electric field, ...
Physics - A computer and monitor use 800J of electric energy each second. The ...
CHEMISTRY - An electron undergoes a transition from an n=3 to an n=1 stationary ...

Search
Members