Glycerine has an index of refraction of 1.47. What is the critical angle for a light ray traveling from:
a)Glycerin into air
b)Glycerin into water
a) I know- n1=1.47 n2=1 angle of refraction=90
1.47(sin.anglei)= sin90
1.47(sin.anglei)=1
sin.anglei=0.6803
angle of incidence=42.865 degrees
b) I know n1=1.47 n2=1.33 angle of refraction=90
1.47(sin.anglei)=1.33
sin.anglei=0.9048
angle of incidence=64.79 degrees
Do I have the right idea? They put it out of a lot of marks so I wondered if I was missing something...
Thanks a bunch :)
Yes, right idea. I did not check arithmetic.
looks good
Thanks guys!!! 99% on my midterm mainly because of your help so your time is very much appreciated :) <3
Yes, you have the right idea. To calculate the critical angle, you can use Snell's law, which relates the angles of incidence and refraction to the refractive indices of the materials.
For case a) where the light ray is traveling from glycerin into air, you correctly identified that n1 (refractive index of glycerin) is 1.47 and n2 (refractive index of air) is 1. The critical angle occurs when the angle of refraction is 90 degrees, which means the light is refracted along the boundary of the two materials. Setting the angle of refraction to 90 degrees in Snell's law, you can solve for the angle of incidence (anglei), which you correctly found to be 42.865 degrees.
For case b) where the light ray is traveling from glycerin into water, you correctly identified that n1 (refractive index of glycerin) is 1.47 and n2 (refractive index of water) is 1.33. Similarly, the critical angle occurs when the angle of refraction is 90 degrees. Setting the angle of refraction to 90 degrees in Snell's law, you can solve for the angle of incidence (anglei), which you correctly found to be 64.79 degrees.
Your calculations appear to be correct. However, it's always a good idea to double-check your work and make sure you have used the correct values for the refractive indices. Also, be sure to include appropriate units for the angles (e.g., degrees) when presenting your final answers.