The $80-\mathrm{cm}$-tall, $65-\mathrm{cm}$-wide tank shown in Figure mentioned is completely filled with water. The tank has marks every $10 \mathrm{~cm}$ along one wall, and the $0 \mathrm{~cm}$ mark is barely submerged. As you stand beside the opposite wall, your eye is level with the top of the water.

a. Can you see the marks from the top of the tank (the $0 \mathrm{~cm}$ mark) going down, or from the bottom of the tank (the $80 \mathrm{~cm}$ mark) coming up? Explain. b. Which is the lowest or highest mark, depending on your answer to part a, that you can see?

What is the angle of incidence in air of a light ray whose angle of refraction in glass is half the angle of incidence?

The place you get your hair cut has two nearly parallel mirrors 5.0 m apart. As you sit in the chair, your head is 2.0 m from the nearer mirror. Looking toward this mirror, you first see your face and then, farther away, the back of your head. (The mirrors need to be slightly nonparallel for you to be able to see the back of your head, but you can treat them as parallel in this problem.) How far away does the back of your head appear to be? Neglect the thickness of your head.

You're helping with an experiment in which a vertical cylinder will rotate about its axis by a very small angle. You need to devise a way to measure this angle. You decide to use what is called an optical lever. You begin by mounting a small mirror on top of the cylinder. A laser $5.0 \mathrm{~m}$ away shoots a laser beam at the mirror. Before the experiment starts, the mirror is adjusted to reflect the laser beam directly back to the laser. Later, you measure that the reflected laser beam, when it returns to the laser, has been deflected sideways by $2.0 \mathrm{~mm}$. Through how many degrees has the cylinder rotated?

Two lightbulbs are 1.0 m apart. From what distance can these lightbulbs be marginally resolved by a small telescope with a 4.0-cm-diameter objective lens? Assume that the lens is diffraction limited and $\lambda=600 \mathrm{nm}$.

A $1.0$-cm-thick layer of water stands on a horizontal slab of glass. Light from a source within the glass is incident on the glass-water boundary. What is the maximum angle of incidence for which the light ray can emerge into the air above the water?

A red ball is placed at point $\mathrm{A}$ in Figure mentioned.

a. How many images are seen by an observer at point $\mathrm{O}$ ? b. What are the $(x, y)$ coordinates of each image?

A $1.0-\mathrm{cm}-\mathrm{tall}$ object is $20 \mathrm{~cm}$ in front of a concave mirror that has a $60 \mathrm{~cm}$ focal length. Calculate the position and height of the image. State whether the image is in front of or behind the mirror, and whether the image is upright or inverted.

An advanced computer sends information to its various parts via infrared light pulses traveling through silicon fibers. To acquire data from memory, the central processing unit sends a light-pulse request to the memory unit. The memory unit processes the request, then sends a data pulse back to the central processing unit. The memory unit takes 0.5 ns to process a request. If the information has to be obtained from memory in 2.0 ns, what is the maximum distance the memory unit can be from the central processing unit?

A red ball is placed at point A. a. How many images are seen by an observer at point $\mathrm{O}$ ? b. What are the $(x, y)$ coordinates of each image? c. Draw a ray diagram showing the formation of each image.

An object is 30 cm in front of a convex mirror with a focal length of -20 cm. Use ray tracing to locate the image. Is the image upright or inverted?

A light beam passing from medium 2 to medium 1 is refracted Is $n_1$ larger than $n_2$, is $n_1$ smaller than $n_2$, or is there not enough information to tell? Explain.

Figure mentioned is the top view of a room. Red and green light bulbs separated by $0.25 \mathrm{~m}$ shine through the door and illuminate the back wall. Over what range of $x$ is the back wall illuminated by (a) the red and (b) the green light?

An object is 12 cm in front of a concave mirror with a focal length of 20 cm. Use ray tracing to locate the image. Is the image upright or inverted?