Q&A Hero

Q: Glass in a florist's greenhouse acts as a one-way valve by A) blocking the flow of light energy. B) blocking unwanted radiation. C) being transparent only to lower-frequency waves. D) allowing high-frequency waves to enter and blocking low-frequency waves from exiting.

Q: The planet Earth loses heat primarily by A) conduction. B) convection. C) radiation. D) all of the above E) none of the above

Q: Waves emitted by the Sun and terrestrial wave emissions are A) the same except for their frequencies and wavelengths. B) entirely different kinds of waves. C) identical.

Q: The interior of a greenhouse emits long-wavelength radiation due to its A) green color. B) plant cell structure. C) transparency. D) relatively low temperature.

Q: Transparency of the atmosphere is lowest for radiation of A) ultraviolet light. B) visible light. C) infrared light.

Q: The atmosphere becomes opaque to infrared radiation when it A) increases in temperature. B) contains excess water vapor and carbon dioxide. C) radiates high-frequency radiation. D) none of the above

Q: Glass is largely opaque to A) infrared light. B) visible light. C) ultraviolet light.

Q: Glass in a florist's greenhouse blocks radiation of relatively A) high frequencies. B) low frequencies. C) all frequencies.

Q: If the greenhouse effect on Earth were absent, Earth's average temperature would be about A) -18C. B) appreciably warmer. C) as it is now.

Q: Compared to a glass of ice water with ice, a glass of plain ice-cold water without ice on a warm day will warm up A) faster. B) slower. C) in the same amount of time.

Q: It is commonly thought that a can of beverage will cool faster in the coldest part of a refrigerator. Knowledge of Newton's law of cooling A) supports this. B) contradicts this. C) is unrelated to this.

Q: A blueberry pie will be a net absorber of energy when its temperature is A) higher than its surroundings. B) lower than its surroundings. C) none of these

Q: An apple pie will be a net emitter of energy when its temperature is A) higher than its surroundings. B) lower than its surroundings. C) neither of these

Q: A red-hot piece of iron will cool slower in a A) cold room. B) warm room. C) same in each

Q: A watermelon will cool faster when placed in what part of a refrigerator? A) the freezer compartment B) the main part of the refrigerator C) either location should cool the can at the same rate

Q: Newton's law of cooling applies to things that are A) cooling. B) warming. C) both of these D) none of the above

Q: To save the most energy when you leave your cool house for an hour or so on a hot day, you should turn the temperature setting on the air conditioner A) down. B) up. C) off. D) to room temperature.

Q: When you leave your warm house for an hour or so on a cold day, to save energy you should turn the thermostat A) down. B) up. C) off. D) to room temperature.

Q: Coffee is served at a restaurant before you are ready to drink it. To be hottest when you are ready to drink it, you should add cream A) right away. B) at any time. C) when you are ready to drink the coffee.

Q: If air were a better conductor than it is, nighttimes on Earth would be A) considerably colder. B) considerably warmer. C) not appreciably different in temperature.

Q: Which body continually emits electromagnetic waves? A) the Sun B) the Earth C) you and your classmates D) all of the above E) none of the above

Q: The silver lining on the glass surfaces of a Thermos bottle reduces energy that is transferred by A) conduction. B) convection. C) radiation. D) friction. E) none of the above

Q: A photovoltaic cell receives energy input primarily by A) conduction. B) convection. C) radiation. D) all of the above

Q: Radiant energy from the Sun is composed of shorter wavelengths than radiation from the Earth because the Sun A) has much more thermal energy. B) has a higher temperature than the Earth. C) is an energy source while the Earth is primarily an energy receiver. D) none of the above

Q: A good reflector of radiation is a A) good absorber of radiation. B) good emitter of radiation. C) poor absorber of radiation. D) none of the above

Q: A good absorber of radiation is a A) good emitter of radiation. B) poor emitter of radiation. C) good reflector. D) none of the above

Q: If a pizza absorbs more energy than it emits, its temperature A) decreases. B) is unaffected. C) increases. D) none of the above

Q: A piece of pizza is normally a net radiator of energy when its temperature is A) higher than its surroundings. B) lower than its surroundings. C) neither of these

Q: The pupil of your eye is a net A) absorber of radiant energy. B) emitter of radiant energy. C) neither of these

Q: To minimize heat loss it is best that a teapot be A) black. B) silver. C) depends on size, not color

Q: Cold water will warm to room temperature faster in a A) black pot. B) silver pot. C) depends on size, not color

Q: Hot water will cool to room temperature faster in a A) black pot. B) silver pot. C) depends on size, not color

Q: If an object absorbs more energy than it emits, its A) thermal energy decreases. B) temperature decreases. C) both of these D) none of the above

Q: If an object radiates more energy than it absorbs, its A) thermal energy decreases. B) temperature decreases. C) both of these D) none of the above

Q: Heat radiation relates mainly to A) infrared radiant energy. B) radiation not visible to humans. C) waves you absorb when near a hot stove. D) all of the above E) none of the above

Q: An infrared thermometer operates by way of A) temperature differences. B) radiant energy invisible to humans. C) conduction, convection, and radiation. D) none of the above

Q: Which emits radiation of the highest frequency? A) a red-hot star B) the Sun C) a blue-hot star D) all the same

Q: A star that is twice as hot as another has twice the A) Celsius temperature. B) Fahrenheit temperature. C) Kelvin temperature. D) all of the above E) none of the above

Q: The higher the temperature of an object, the A) longer the wavelengths it radiates. B) shorter the wavelengths it radiates. C) none of the above

Q: The higher the temperature of an object, the A) higher the frequency of emitted radiation. B) lower the frequency of emitted radiation. C) longer the wavelength of emitted radiation. D) none of the above

Q: Peak frequency as noted on a radiation curve is directly proportional to the A) frequency of waves emitted. B) wavelength of waves emitted. C) temperature of emitted radiation. D) temperature of the emitter. E) none of the above

Q: The average frequency of radiant energy is directly proportional to the A) Celsius temperature of the emitter. B) Fahrenheit temperature of the emitter. C) kelvin temperature of the emitter. D) all of the above E) none of the above

Q: The higher the frequency of a wave, the A) shorter the wavelength. B) longer the wavelength. C) neither of these

Q: Radiant energy emitted by our planet is A) terrestrial energy. B) the outcome of radioactivity in Earth's interior. C) electromagnetic. D) all of the above

Q: A substance most commonly emits heat energy by the process of A) conduction. B) convection. C) radiation. D) none of the above

Q: The gush of steam that issues from the escape valve of a pressure cooker is relatively cool A) close to the opening. B) above the opening where vapor is visible. C) both of these D) none of the above

Q: Hot steam that issues from a pressure cooker expands and A) increases in temperature. B) can cause severe burns. C) cools. D) all of the above E) none of the above

Q: When air is compressed, its temperature A) increases. B) decreases. C) neither of these

Q: If a volume of air is warmed, it expands. If a volume of air expands, it A) warms. B) cools. C) neither of these

Q: Blow on your hand and you feel the warmth of your breath. Pucker your lips so your breath expands as you blow and your breath is A) still warm. B) cool. C) neither of these

Q: Coastal winds that shift from night to day illustrate A) conduction. B) convection. C) radiation. D) all about equally

Q: Convection currents in the air near a seashore are produced by A) shifting winds. B) unequal heating of land and water. C) varying temperatures. D) none of the above

Q: Warm air rises because faster moving molecules tend to move to regions of less A) density. B) pressure. C) both of these D) none of the above

Q: The process of convection occurs in A) solids. B) liquids. C) gases. D) fluids. E) none of the above

Q: A water-filled paper cup held in a flame will not catch fire because A) the inside of the paper is wet. B) water is an excellent conductor of heat. C) paper is a good conductor of heat. D) the paper cup cannot become appreciably hotter than the water it contains.

Q: A bare roof of a warmly heated home on a snowy day indicates A) an unwanted flow of heat. B) good insulation. C) a change of phase. D) all of the above

Q: The main reason you can walk barefoot on red-hot coals of wood without burning your feet involves A) low temperature of the coals. B) low conductivity of the coals. C) mind over matter techniques.

Q: Wood is a poor conductor A) when it is cold. B) at room temperature. C) when it is hot. D) all of the above E) none of the above

Q: In terms of transferring heat, red-hot wooden coals A) conduct quite well. B) conduct poorly. C) radiate poorly. D) convect poorly.

Q: If you were caught in freezing weather with only a candle for warmth, you would be warmer in A) an igloo. B) a tent. C) a wooden house.

Q: Your bare feet feel warmer on a rug than on a tile floor because the rug A) is usually warmer than tile. B) is a better insulator than tile. C) has more thermal energy than tile. D) all of the above E) none of the above

Q: When you touch a nail stuck in ice, energy flows from A) the ice to your hand. B) your hand to the ice. C) both of these D) none of the above

Q: A block of wood and a block of copper will feel neither hot nor cold to your touch when they each have A) equal temperatures. B) your temperature. C) equal conductivities. D) none of the above

Q: Because of trapped air inside, snow is a A) poor conductor. B) good insulator. C) both of these D) none of the above

Q: Which of these are good insulators? A) feathers B) wood C) snow D) all the above E) none of the above

Q: Which of these are good conductors? A) feathers B) wood C) snow D) all the above E) none of the above

Q: A poor conductor of heat is a A) poor insulator. B) good insulator. C) neither

Q: Spun glass is a relatively A) good conductor. B) poor conductor. C) both about the same

Q: In practice, a good insulator A) stops heat flow. B) slows heat flow. C) speeds negative heat flow. D) all of the above

Q: A good heat conductor is a A) poor insulator. B) good insulator. C) neither of these

Q: Metals are both good heat and electrical conductors due to A) similar thermal and electrical conductive properties. B) looseness of outer electrons in metal atoms. C) relatively high densities of metals. D) high elasticity of metals. E) ability of metals to transfer energy easily.

Q: Conduction has most to do with electrons and atoms A) bumping into one another. B) flowing past one another. C) radiating energy. D) changing identities.

Q: Increasing the temperature of 50 grams of water by 1C requires A) 1 calorie. B) 50 calories. C) more than 50 calories. D) none of the above

Q: The number of joules in 1 kilocalorie is A) 4.19. B) 41.9. C) 4190. D) 1054.

Q: San Francisco Chef Manual rates the energy content of foods in units of A) calories. B) Calories. C) joules. D) Celsius degrees.

Q: A nutritionist in the United States measures food energy in units of A) kilocalories. B) Calories. C) both are the same D) neither of the above

Q: Thermal energy is measured in A) calories. B) Calories. C) joules. D) any or all of the above for special cases

Q: White-hot sparks from a fireworks sparkler that strike your skin don't cause injury because A) they have a low temperature. B) the energy per molecule is very low. C) the energy per molecule is high, but the total energy transferred is small.

Q: Compared to a giant iceberg, a hot cup of coffee has A) more thermal energy at higher temperature. B) less thermal energy at higher temperature. C) about the same thermal energy but at a higher temperature. D) none of the above

Q: If a room is cold it is usually due to the A) lack of adequate thermal energy. B) low air pressure. C) presence of the entity known as cold.