Science Buddies: "Ask an Expert"

i need to know how too do optics and trigonometry.... i have no clue what it is... .... i am doing for a project " measureing the speed of light through gelatin" please help me and i need too know now plz someone help me....
i would be if someone did.... can you also explain it to me plz

Have you read all of the information in this Science Buddies project? https://www.sciencebuddies.org/science- ... p009.shtml

If not, start there. If you have specific questions about specific steps on the proceedure we can help. If you have questions about the background of the project that aren't covered on the background tab, there are several good references on that tab.

idk how to do the snell's law thing.... can you help me with that plz..... oh and thanks for the help

all so i have read all of that from the web site u sent me but i still cant figure it out..... i looked at the web site it had for snell's law but there are three different fomulas and i don't know which one to do.... so once again can you help plz

Have you had a course in algebra yet? Based on your confusion about there being different equations represented as Snell's law, I'm guessing not yet.

In reviewing the references, I only found two algebraic equivalent representations of Snell's law:

A product form:
index_of_refraction_media_1 * sin(angle_media_1) = index_of_refraction_media_2 * sin(angle_media_2)

and a ratio form:
index_of_refraction_media_1 / index_of_refraction_media_2 = sin(angle_media_2) / sin(angle_media_1)

With some algebraic manipulation, you can solve for:
index_of_refraction_media_2 = index_of_refraction_media_1 * (sin(angle_media_1) / sin(angle_media_2)

If media_1 is air, then you can look up the index of refraction of air several places (aproximately 1.0003).
You have to measure the two angles.
You can look up the Trigonometric Sin function value for the two angles (or use a calculator to determine the Sin of an angle from the angle in degrees).
Using either formula and some algebra, you can solve for the index of refraction of your unknown (or use the equation I derived using algebraic manipulation).

By definition, the speed of light in a material is the speed of light in a vaccum (typically 299792458 meters/second) divided by the index of refraction in the material.

Hope this helps you.