Short Answer

26.

Describe one way in which heat waves—infrared radiation—are different from sound waves.

Sound waves are transverse waves, whereas heat waves—infrared radiation—are longitudinal waves.
Sound waves have shorter wavelengths than heat waves.
Sound waves require a medium, whereas heat waves—infrared radiation—do not.
Sound waves have higher frequencies than heat waves.

27 .

Describe the electric and magnetic fields that make up an electromagnetic wave in terms of their orientation relative to each other and their phases.

28 .

Explain how X-radiation can be harmful and how it can be a useful diagnostic tool.

Overexposure to X-rays can cause HIV, though normal levels of X-rays can be used for sterilizing needles.
Overexposure to X-rays can cause cancer, though in limited doses X-rays can be used for imaging internal body parts.
Overexposure to X-rays causes diabetes, though normal levels of X-rays can be used for imaging internal body parts.
Overexposure to X-rays causes cancer, though normal levels of X-rays can be used for reducing cholesterol in the blood.

29 .

Explain how sunlight is the original source of the energy in the food we eat.

Sunlight is converted into chemical energy by plants; this energy is released when we digest food.
Sunlight is converted into chemical energy by animals; this energy is released when we digest food.
Sunlight is converted into chemical energy by fish; this energy is released when we digest food.
Sunlight is converted into chemical energy by humans; this energy is released when we digest food.

30.

Describe what happens to the path of light when the light slows down as it passes from one medium to another?

31 .

What is it about the nature of light reflected from snow that causes skiers to wear polarized sunglasses?

32.

How many lumens are radiated from a candle which has an illuminance of 3.98 lx at a distance of 2.00 m?

33.

Saturn is 1.43×1012 m from the Sun. How many minutes does it take the Sun’s light to reach Saturn?