SNELL'S Law and HEAT的問題,,急=]

圖片參考：http://i182.photobucket.com/albums/x4/A_Hepburn_1990/snellslaw.jpg?t=1182348020


As shown above, the refractive index, n increases with density. This is for EM wave (light ray).

By Snell's law, we have


圖片參考：http://i182.photobucket.com/albums/x4/A_Hepburn_1990/equationforSnellslaw.jpg?t=1182348633


So, When n1 increases, that is the density of medium 1 increases, so v1 decreases (for constant v2). Therefore, θ1 increases.

When n2 increases, that is the density of medium 2 inceases. θ2 increases by the same principle.

So, when density increases, θ will increase. This is true for light. (EM wave)



1. When a lum of ice is placed into a cup of water, it should be internal energy flow from the water to the ice. So it is C.

For the same P.E. for the ice and the water, the internal energy of water should be higher than that of the ice. (because liquid has a higher average K.E. than solid.) So, internal energy will flow from higher concentration (amount) to lower.

For A, heat may not necessarily flow. As the water and the ice can be at the same temperature (0 ℃). So at the same temperature, they are at thermal equilibrium and no heat will flow between them.

For B, the reason is stated above.

For D, particles will not flow from one to each other...

勁~~好得