Chapter 25

Chapter 25

Problems & Exercises

1.

Top 1.715 m1.715 m from floor, bottom 0.825 m0.825 m from floor. Height of mirror is 0.890 m0.890 m, or precisely one-half the height of the person.

5.

2.25×108 m/s2.25×108 m/s in water

2.04×108 m/s2.04×108 m/s in glycerine

7.

1.4901.490, polystyrene

9.

1 . 28 s 1 . 28 s

11.

1.03 ns 1.03 ns

13.

n=1.46n=1.46, fused quartz

17.

(a) 0.898

(b) Can’t have n<1.00n<1.00 since this would imply a speed greater than cc.

(c) Refracted angle is too big relative to the angle of incidence.

19.

(a) c5.00c5.00

(b) Speed of light too slow, since index is much greater than that of diamond.

(c) Angle of refraction is unreasonable relative to the angle of incidence.

22.

66 . 3º 66 . 3º

24.

> 1 . 414 > 1 . 414

26.

1.50, benzene

29.

46 . 5º , red; 46 . 0º , violet 46 . 5º , red; 46 . 0º , violet

31.

(a) 0.043º0.043º

(b) 1.33 m1.33 m

33.

71.3º 71.3º

35.

53.5º , red; 53.5º , red; 55.2º , violet 55.2º , violet

37.

5.00 to 12.5 D 5.00 to 12.5 D

39.

− 0.222 m − 0.222 m

41.

(a) 3.43 m

(b) 0.800 by 1.20 m

42.

(a) −1.35 m−1.35 m (on the object side of the lens).

(b) +10.0+10.0

(c) 5.00 cm

43.

44.4 cm

45.

(a) 6.60 cm

(b) –0.500

47.

(a) +7.50 cm+7.50 cm

(b) 13.3 D13.3 D

(c) Much greater

49.

(a) +6.67

(b) +20.0

(c) The magnification increases without limit (to infinity) as the object distance increases to the limit of the focal distance.

51.

− 0 . 933 mm − 0 . 933 mm

53.

+0.667 m

55.

(a) –1.5×10–2m–1.5×10–2m

(b)–66.7 D–66.7 D

57.

+0.360 m (concave)

59.

(a) +0.111

(b) -0.334 cm (behind “mirror”)

(c) 0.752cm

61.
m = h i h o = − d i d o = − − d o d o = d o d o = 1 ⇒ h i = h o m = h i h o = − d i d o = − − d o d o = d o d o = 1 ⇒ h i = h o
63.

6.82 k W/m 2 6.82 k W/m 2

65.

(a) v 610 = 3.00× 10 8 1.530 m/s,  v 410 = 3.00× 10 8 1.514 m/s 3.00× 10 8 1 1.514 − 1 1.530 m/s=2.07× 10 6  m/s v 610 = 3.00× 10 8 1.530 m/s,  v 410 = 3.00× 10 8 1.514 m/s 3.00× 10 8 1 1.514 − 1 1.530 m/s=2.07× 10 6  m/s

(b) No.

(c) No.

(d) Yes.

Test Prep for AP® Courses

1.

(c)

3.

(c)

5.

(a)

7.

Since light bends toward the normal upon entering a medium with a higher index of refraction, the upper path is a more accurate representation of a light ray moving from A to B.

9.

First, measure the angle of incidence and the angle of refraction for light entering the plastic from air. Since the two angles can be measured and the index of refraction of air is known, the student can solve for the index of refraction of the plastic.

Next, measure the angle of incidence and the angle of refraction for light entering the gas from the plastic. Since the two angles can be measured and the index of refraction of the plastic is known, the student can solve for the index of refraction of the gas.

11.

The speed of light in a medium is simply c/n, so the speed of light in water is 2.25 × 108 m/s. From Snell’s law, the angle of incidence is 44°.

13.

(d)

15.

(a)

17.

(a)

19.

(b)