1. Vibration is the source of wave motion.
2. A wave is disturbance that moves through a medium or through space. A pulse is a nonrepeated disturbance that carries energy through a medium or through space. A wave is a periodic disturbance. A pulse is a one-time disturbance.
3. f = 1/t, the period is halved.
4. (a) Increases (b) Decreases (c) Doesn’t change
5. 448 THz
6. (a) 0.248 m (b) No (c) 0.0411 m
7. 8 minutes 20 seconds
8. 0.122 m
9. 25°, First Law
10. 68°
11. 1.34
12. Light that takes a path from point A to point B will take the same reverse path in going from point B to point A, even if reflection or refraction is involved. So if you can’t see the driver, the driver can’t see you.
13. In spearing a fish with a spear, you should aim below the apparent position of the fish to account for the refraction of the light that you see coming from the fish that makes the fish appear closer to the surface than it really is. In spearing a fish with a laser, make no corrections and simply aim directly at the fish. This is because the light from the fish you see has been refracted in getting to you, and the laser light will refract along the same path in getting to the fish.
14. Light pulses move easily down the fiber-optic line because of a principle known as total internal reflection. This principle of total internal reflection states that when the angle of incidence exceeds a critical value, light cannot get out of the glass; instead, the light bounces back in. When this principle is applied to the construction of the fiber-optic strand, it is possible to transmit information down fiber lines in the form of light