Thank you for your question! This sounds like a fun project and I will be interested to learn what you find out.
Is this the one you are doing? http://www.sciencebuddies.org/science-f ... #materials
For this project you will need a UV monitor, it costs about $25 on Amazon (look for the link on the project page). Keep in mind that this tool is not very effective for measuring UV for lightbulbs. As far as the light is concerned, sunny weather will be an issue for you, and the UV index is low. You can definitely do this project indoors using a UV light. Read the project to learn more about the different wavelengths of ultraviolet light. You can buy a black light, which will provide you with UVA light.
If you go the lightbulb route, you will need additional UV blocking safety glasses, which you can find on amazon or industrial materials store.
Here are some questions for you to explore:
What did you find out about different sunscreens: which lightwaves do they block? What is the difference between long (ultraviolet A), medium (ultraviolet B), short wavelengths (ultraviolet C) and how does each affect the person exposed to them? How does low UV index affect the effectiveness of sunscreens.
Here is a good start for information on sunscreens.http://en.wikipedia.org/wiki/Sunscreenhttp://www.presun.com/UV.htmlhttp://www.epa.gov/sunwise/uviscale.html
1. One thing you might do is to use UVA/ blacklight instead of how the experiment is normally setup. You can discuss the significance of UVA light and how it differs in coverage than UVB light.
2. Another idea is to complete the experiment where you live, even though it is cold, the UV index can still be high. Also, because of the reflectiveness of snow (and also water), this causes sunlight to bounce of the surface and onto our skin. That is why you can still get a sunburn while being in the snow (see weblinks above for more explanation).
3. Questions to consider, and putting into your final analysis/ conclusions: Does UV index affect whether or not sunscreen is effective? Why do skiiers wear sunscreen even in the cold weather? Can you get a sunburn when it is cloudy outside?
Please let me know if any of that information was confusing or you have more questions about it. I'd be glad to help and follow your progress. Cheers!