A piece of glass is immersed in water. If a light ray enters the glass from the water with an angle of incidence greater than zero, in which direction is the ray bent?

Unless indicated otherwise, assume the speed of sound in air to be v = 344 m/s. You live on a busy street, but as a music lover, you want to reduce the traffic noise. (a) If you install special sound reflecting windows that reduce the sound intensity level (in dB) by 30 dB, by what fraction have you lowered the sound intensity (in $W/m^{2}$)? (b) If, instead, you reduce the intensity by half, what change (in dB) do you make in the sound intensity level?

You live on a busy street, but as a music lover, you want to reduce the traffic noise.
(b) If, instead, you reduce the intensity by half, what change (in $\mathrm{dB}$) do you make in the sound intensity level?

(a) What is the difference between specular reflection and diffuse reflection? (b) Provide some examples of both specular and diffuse reflection.

Which type of EM wave does your body emit most strongly?

Explain how electromagnetic waves are a natural outcome of the principles of electromagnetism.

A string on the violin has a length of 24.00 cm and a mass of 0.860 g. The fundamental frequency of the string is 1.00 kHz. (a) What is the speed of the wave on the string? (b) What is the tension in the string?

Oscillation of a 600 Hz tuning fork sets up standing waves in a string clamped at both ends. The wave speed for the string is 400 m/s. The standing wave has four loops and an amplitude of 2.0 mm. What is the length of the string?

What is different about an image formed with a convex mirror compared to an image formed with a concave mirror? What are the advantages of each type of mirror?

Vibrations from a $622$-$\mathrm{Hz}$ tuning fork set up standing waves in a string clamped at both ends. The wave speed for the string is $388$ m/s. The standing wave has four loops and an amplitude of $1.90$ mm. (a) What is the length of the string?
(b) Write an equation for the displacement of the string as a function of position and time.

we described how the speed of light varies with wavelength (or frequency) for transparent solids. But the speed of light in matter is also a function of temperature and pressure. This dependence is most marked for gases and is instrumental in producing such things as mirages and atmospheric refraction, the latter phenomenon being the displacement of an astronomical object (like the Sun or another star) from its true position because of the passage of its light through the atmosphere. Because Earth's atmosphere is a gaseous mixture and easily compressed, its density is highest near Earth's surface and gradually declines with altitude. Thus, the speed of light in the atmosphere is lowest near the surface and gradually gets higher, approaching $c$ as one goes farther and farther into space. Using this fact and the law of refraction, sketch the path a light ray from the Sun would follow upon entering Earth's atmosphere, and predict the apparent position of the Sun relative to its true position. What does this tell you about the actual location of the Sun's disk relative to your local horizon when you see it apparently setting brilliantly in the west in the evening?

The speed of light in a certain kind of glass is exactly the same as the speed of light in benzene-a liquid. Describe what happens when light passes from benzene into this glass, and vice versa.

How would figure mentioned $\mathrm{a}$ be different if the glass were replaced by water or by diamond?

Describe how the path of a ray is deviated as it passes (at an angle) from one medium into a second medium in which the speed of light is lower. Contrast this with the case when the speed of light in the second medium is higher.