Compute the approximate ratio of the amount of blue light in scattered sky light to the amount of orange.

A salesperson at a bargain counter claims that a certain pair of sunglasses has Polaroid filters; you suspect that the glasses are just tinted plastic. How could you find out for sure?

Sometimes when looking at a window, you see two reflected images slightly displaced from each other. What causes this?

When hot air rises from a radiator or heating duct, objects behind it appear to shimmer or waver. What causes this?

Sunlight or starlight passing through the earth’s atmosphere is always bent toward the vertical. Why? Does this mean that a star is not really where it appears to be? Explain.

An observer $O$ stands in front of a plane mirror. Which of the numbered locations 1 through 5 best represents the location of the image of the source $S$ seen by the observer? Justify your choice by appealing to the anoropriate law (s) of optics.

A 2.0-cm-tall object is located 8.0 cm in front of a converging lens with a focal length of 10 cm. Use ray tracing to determine the location and height of the image. Is the image upright or inverted? Is it real or virtual?

A fish looks up toward the surface of a pond and sees the entire panorama of clouds, sky, birds, and so on, contained in a narrow cone of light, beyond which there is darkness. What is going on here to produce this vision, and how large is the opening angle of the cone of light received by the fish?

A light ray in air enters a block of clear plastic. Which of the numbered paths represents the correct one for the ray in the plastic? Justify your choice by appealing to the appropriate law(s) of optics.

Light traveling along direction $\mathrm{SO}$ strikes the surface of a plane mirror. Which of the paths $O P, O Q, O R$, or $U I$ best describes the path of the light reflected from the mirror? Defend your choice by appealing to the appropriate law(s) of optics.

If the mirror described in the previous problem is used to form an image of the same object now located $16 \mathrm{~cm}$ in front of the mirror, what would the new image position be? Assuming that the magnification equations developed for lenses also apply to mirrors, describe the image thus formed.

The equation connecting $s, p$, and $f$ for a simple lens can be employed for spherical mirrors, too. A concave mirror with a focal length of $8 \mathrm{~cm}$ forms an image of a small object placed $10 \mathrm{~cm}$ in front of the mirror. Where will this image be located?

The equation connecting $s, p$, and $f$ for a simple lens can be employed for spherical mirrors, too. A concave mirror with a focal length of $8 \mathrm{~cm}$ forms an image of a small object placed $10 \mathrm{~cm}$ in front of the mirror. Where will this image be located?

A light ray traveling in air strikes the surface of a slab of glass at an angle of incidence of $50^{\circ}$. Yart of the light is retlected and part is refracted. Find the angles the reflected and refracted rays make with respect to the normal to the air-glass interface.