Posted by **Lynn** on Monday, February 21, 2011 at 10:59pm.

A 100.0 W light bulb hangs from the ceiling. What is the visible light intensity on the floor, 2.1 m directly below the bulb, if 10% of its output is visible light?

So I am attempting to use: I= Power/area

however, I don't have a radius. I know 10% of 100 is 10 so that would be the intensity for that and that the refraction for air should be used but I am missing something...

HELP :)

## Answer this Question

## Related Questions

- Physics - We can reasonably model a 75 W incandescent light bulb as a sphere 6....
- Physics - A 100 watt bulb emits light in all directions. The distance R from ...
- Physics - We can reasonaly model a 75 W incandescent lightbulb as a sphere 6 cm ...
- physics - You are in the lab with a 10 V battery. You have a 10 W light bulb and...
- college physics - You are in the lab with a 10 V battery. You have a 10 W light ...
- Physics/Algebra - Physics: For a 225-watt bulb, the intensity I of light in ...
- College Physics - The power dissipated by a light bulb increases by 50 W when ...
- algebra - The intensity I of light bulb measured in watts per square meter (w/m^...
- physics - A light bulb is wired in series with a 133-Ω resistor, and they ...
- Introduction to Electricity and Circuits - A light bulb is wired in series with ...

More Related Questions