What is the ideal shape of concave mirrors used in telescopes?

A small object is placed to the left of a convex lens and on its optical axis. The object is $30 \mathrm{~cm}$ from the lens, which has a focal length of $10 \mathrm{~cm}$. Determine the location of the image formed by the lens. Describe the image.

An object is placed to the left of a convex lens with a 25-mm focal length so that its image is the same size as the object. What are the image and object positions?

What are the highest-frequency and lowest-frequency parts of the EM spectrum?

As the footnote on above page indicates, the separation, $\Delta x$, between two adjacent bright areas or fringes in the double slit interference pattern is determined by the distance, $a$, between the slits, the distance, $S$, between the plane of the slits and the screen on which the pattern is projected, and the wavelength, $\lambda$, of light used in the experiment. Specifically, the relationship among these variables is given by:

$$\Delta x=\left(\frac{S}{a}\right) \lambda .$$

Based on this equation, for a given slit spacing and screen distance, for which color of light, red or blue, will the fringe spacing be greater? For a given slit spacing and wavelength, if the screen distance, $S$, is increased, what happens to the fringe spacing? If the separation between the slits is decreased, for a given value of $\lambda$ and $S$, how will $\Delta x$ change? Suppose that a beam of red light from a He-Ne laser $(\lambda=633 \mathrm{~nm})$ strikes a screen containing two narrow slits separated by $0.200 \mathrm{~mm}$. The fringe pattern is projected on a white screen located $1.00 \mathrm{~m}$ away. Find the distance in millimeters between adjacent bright areas near the center of the interference pattern that develops. As mentioned in the text, the relationship given above could be used to calculate the wavelength of light in an experiment in which the other three quantities are measured.

An electric clothes dryer used 4400 W to dry two loads of laundry. Electricity costs 5.6 $c/kW \cdot h$. If it cost 75c to use the dryer, for approximately how many hours did the dryer operate?

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?

List several examples of the use or application of Fresnel lenses in today's world.

Distinguish between specular reflection and diffuse reflection.

In a double-slit interference experiment, a special lamp emitting yellow light from heated sodium atoms is used to produce an interference pattern on a screen located $1.50$ m from a pair of slits separated by $0.10 \mathrm{~mm}$. If the distance between adjacent bright regions in the resulting pattern is $8.84 \mathrm{~mm}$, what is the wavelength of the sodium light?

A person riding on a bus hears the sound from a horn on a car that is stopped. What is different about the sound when the bus is approaching the car compared to when the bus is moving away from the car?

Two plane mirrors are hinged along one edge and set at right angles to one another as shown in Figure mentioned. A light ray enters the system, striking mirror 1 with an angle of incidence of $45^{\circ}$. Draw a diagram showing the direction in which the ray will exit the system. This device is called a corner reflector and is the basis for the design of bicycle reflectors and some highway signs.

What do you see if you hold out your right hand in front of an aeroplane mirror? (Be cautious now. Describe the image carefully.) If you’re having trouble, place a tube of toothpaste or other object with writing on it in front of the mirror. Now what can you say? (The process you’re witnessing is called inversion and is one of the common characteristics of plane mirrors.)

The generator at a power plant produces $A C$ at 24,000 V. A transformer steps this up to $345,000 \mathrm{~V}$ for transmission over power lines. If there are 2,000 turns of wire in the input coil of the transformer, how many turns must there be in the output coil?