Below are links to websites that can help you study for the Minnesota Comprehensive Assessment. (MCA)
The brainpop website below is an excellent source of information for all grades. I recommend that you get yourseulf an account even just a trial account. (no..We are not being paid to say that :). A Trial account will last for 5 days and give you a good source of information. I have included a username and password that you are welcome to use. I do not know what will happen if more than one persion tries to use the account at the same time, but it can't hurt to try.
http://www.brainpop.com/
Username: moosesito
Password: moose
For more specific websites check below.
Physics
http://www.physics4kids.com/ Physics for Kids is a general physics website with lots of references and explanations.
http://www.colorado.edu/physics/2000/index.pl Lots of really cool little applets that demostrate the Physics of Light.