A beam of light in air is incident at an angle of 40 degrees on the surface of a transparent solid. The Light is deveated by 15 degrees toward the normal upon entering the solid. What is the critical angle for the total internal reflection from within the solid?
2007-02-22 22:27:50 · 2 answers · asked by ncaafan2 2 in Science & Mathematics ➔ Physics
after refraction the angle r is 40-15 =25
as n(air) sin i = n sinr and n(air) =1 i =40 r =25
n= sin 40/sin 25 =0.643/0.423=1.56
the critical angle has for sin 1/1.56 0.644
it corresponds to an angle of 40°
2007-02-22 22:45:58 · answer #1 · answered by maussy 7 · 1⤊ 0⤋
Maussy I think has it right !!
Have a look at this site for some good examples of refraction / reflection & examples....
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/refrn/u14l3c.html
2007-02-22 22:47:50 · answer #2 · answered by Doctor Q 6 · 0⤊ 0⤋