Use the exact values you enter to make later calculations. A ray of light strike

Question

Use the exact values you enter to make later calculations. A ray of light strikes a flat, 2.00-cm-thick block of glass (n = 1.60) at an angle of theta = 39.4 degree with respect to the normal (see figure below). (a) Find the angle of refraction at the top surface and the angle of incidence at the bottom surface. degree (b) Find the refracted angle at the bottom surface. degree (c) Find the lateral distance d by which the light beam is shifted. cm (d) Calculate the speed of light in the glass. m/s (e) Calculate the time required for the light to pass through the glass block. (f) Is the travel time through the block affected by the angle of incidence? Yes, a slightly larger angle will decrease the travel time. No Yes, a slightly larger angle will increase the travel time.

Explanation / Answer

a)
na*sini1 = ng*sinr1

sinr1 = na*sini1/ng

r1 = arcsin(na*sini1/ng)

= arcsin(1.00*sin39.4/1.60)

= 23.37 degrees

b)
ng*sini2 = na*sinr2

sinr2 = ng*sini2/na

r2 = arcsin(ng*sini2/na)

= arcsin(1.60*sin23.37/1.00)

= 39.4 degrees

c)
h = l / cosr1
= 2/cos23.37
= 2.179 cm

d = h*sin(39.4-23.37)
= 2.179*sin(16.03)
= 0.602 cm

d)
v = (3*10^8)/1.60
= 1.875*10^8 m/s

e)
t = h/v = (2.179*10^-2)/(1.875*10^8)
= 1.16*10^-10 s = 0.116 ns

f) Option a

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.