NS 101 Chapter 7

Which of the following is luminous?

• moon

• mars

• sun

• all of the above

Comparing measurements made on the ground to measurements made in a very fast airplane would find that

• the length of an object is shorter.

• clocks run more slowly.

• objects have an increased mass.

• all of the above are true.

The general theory of relativity explains

• gravity as a change of space and time.

• why the speed of light changes with the speed of an observer

• how the laws of physics change with changes of motion.

• Newton’s laws of motion.

The special theory of relativity is

• a new explanation of gravity.

• an analysis of how space and time are changed by motion.

• an analysis of how fast-moving clocks run faster.

• based on a changing velocity of light.

An instrument that produces a coherent beam of single-frequency, in-phase light is a

• telescope

• laser

• camera

• solar cell

Today, light is considered to be a stream of photons with a frequency related to its energy. This relationship finds that

• frequencies near the middle of the spectrum have more energy.

• more energetic light is always light with a lower frequency.

• higher-frequency light has more energy.

• lower-frequency light has more energy.

The condition of farsightedness, or hyperopia, can be corrected with a (an)

• concave lens.

• convex lens.

• eyepiece lens.

• combination of convex and concave lenses

Polaroid sunglasses work best in eliminating glare because

• reflected light is refracted upward.

• unpolarized light vibrates in all possible directions.

• reflected light undergoes dispersion.

• reflected light is polarized in a horizontal direction only.

A glass prism separates sunlight into a spectrum of colors because

• shorter wavelengths are refracted the most

• light separates into colors when reflected from crystal glass.

• light undergoes absorption in a prism.

• there are three surfaces that reflect light

A mirage is the result of light being

• reflected

• refracted

• absorbed

• bounced around a lot