phys Exam 4
Group Exam
#4
The amount of heat needed to raise the temperature of 1 gram of water by 1°C is
A. 4.19 Calories. B. [4.19 joules.] C. 4.19 calories. D. none of the above
When 10 grams of hot water cool by 1°C, the amount of heat given off is
A. 41.9 calories. B. [41.9 joules.] C. more than 41.9 joules. D. 41.9 Calories. E. none of the above
Which is the better statement?
A. A black object absorbs energy well. B. [An object that absorbs energy well is black.] C. Both say the same thing, so both are equivalent. D. Both are untrue. This is a cause-and-effect question. The color black doesn't draw in and absorb energy. It's the other way around—any object that does draw in and absorb energy, will, by consequence, be black in color.
Which star has the higher temperature?
A. A red-hot star B. [A blue-hot star] C. A white-hot star D. Not enough information for an answer.
Slide Questions
ch 15 (Temperature, heat, expansion)
Slide Questions
ch 16 (heat)
slide questions
ch 17 (phase changes)
Quiz
8
Quiz
9
Absolute zero corresponds to a temperature of
A. 0 K. B. -273ºC C. [Both of these.] D. None of these. Kelvin = 273 + C; 0 K = -273ºC
You heat a half-cup of tea and its temperature rises by 4°C. How much will the temperature rise if you add the same amount of heat to a full cup of tea?
A. 0°C B. [2°C] C. 4°C D. 8°C
The amount of heat needed to raise the temperature of 1 g of water by 1°C is ___________.
A. 1 newton B. 1 joule C. 1 joule or 1 calorie, as both are the same D. [1 calorie]
Water is most dense at ___________.
A. 100°C B. 0°C C. [4°C] D. less than 0°C Density of ice at any temperature is much lower than the density of water, which is why ice floats on water. Ice forms when water is less than 0°C. The temperature of melting ice is 0°C.
When you step out after a hot shower you feel cold, but you can feel warm again if you step back into the shower area. Which process is responsible for this?
A. Evaporation B. [Condensation] C. Both of these. D. None of the above. When you step back into the shower area, the steam that is present condenses on your body, causing it to warm up.
Which of these electromagnetic waves has the shortest wavelengths?
A. Infrared B. Visible C. Ultraviolet D. [Gamma rays]
Which body glows with electromagnetic waves?
A. Sun B. Earth C. [Both A and B.] D. None of the above. Earth glows in long-wavelength radiation, while the Sun glows in shorter waves.
Although warm air rises, why are mountaintops cold and snow covered, while the valleys below are relatively warm and green?
A. Warm air cools when rising. B. There is a thick insulating blanket of air above valleys. C. [Both A and B.] D. None of the above. Earth's atmosphere acts as a blanket, which keeps the valleys from freezing at nighttime.
If you hold one end of a metal bar against a piece of ice, the end in your hand will soon become cold. Does cold flow from the ice to your hand?
A. Yes B. In some cases, yes C. [No] D. In some cases, no Cold does not flow from the ice to your hand. Heat flows from your hand to the ice. The metal is cold to your touch because you are transferring heat to the metal.
The temperature of absolute zero is stated as ___________.
A. [-273°C] B. 273K C. kelvin D. 32°C
Which involves the greatest number of calories?
A. [Condensing 1 gram of 100°C steam to 100° water] B. Cooling 1 gram of 100°C water to 1 gram of 0°C ice C. Cooling 1 gram of 0°C ice to near absolute zero D. All about the same. 540 calories is more than the 100 calories for B, and half of 273 calories to cool ice (the specific heat of ice is about half that for liquid water).
Which melts faster in sunshine—dirty snow or clean snow?
A. [Dirty snow] B. Clean snow C. Both A and B. D. None of the above. Dirty snow absorbs more sunlight, whereas clean snow reflects more.
Which of these electromagnetic waves has the lowest frequency?
A. [Infrared] B. Visible C. Ultraviolet D. Gamma rays
There is twice as much molecular kinetic energy in 2 liters of boiling water as in 1 liter of boiling water. Which will be the same for both?
A. [Temperature] B. Thermal energy C. Both A and B. D. Neither A nor B. Average kinetic energy of molecules is the same, which means temperature is the same for both.
Which of these has the highest specific heat capacity?
A. [Water] B. Iron C. Soil D. Silver Water has an appreciably higher specific heat capacity than other common materials.
Which has the higher specific heat capacity, water or land?
A. [Water] B. Land C. Both of the above are the same. D. None of the above. A substance with small temperature changes for large heat changes has a high specific heat capacity. Water takes much longer to heat up in the sunshine than does land. This difference is a major influence on climate.
Compared to sea level, water in an open pot in the mountains boils at
A. [a lower temperature.] B. a higher temperature. C. the same temperature. D. none of the above
Evaporation is a cooling process and condensation is
A. [a warming process.] B. a cooling process also. C. neither of these
The air in your room is composed of molecules that have
A. [a wide variety of speeds.] B. no speeds worth mentioning. C. nearly identical speeds.
When a gas changes phase to become a plasma, energy is
A. [absorbed.] B. given off. C. unchanged. D. in effect multiplied.
When ice changes phase to become water, energy is
A. [absorbed.] B. given off. C. unchanged. D. in effect multiplied.
Double-pane windows contain nitrogen rather than air to prevent
A. [condensation.] B. heat flow. C. thermal conduction. D. gas escape.
When air rapidly expands, its temperature normally _________.
A. [decreases] B. is unaffected, but not always C. remains unchanged D. increases
Thermal conduction has most to do with
A. [electrons.] B. protons. C. neutrons. D. ions. Explanation: material with loosely held electrons transfer energy quickly to other electrons throughout the solid.
Thermal conduction mostly involves the motion of _________.
A. [electrons] B. atoms C. neutrons D. air molecules
When a sample of 4°C water is cooled, it
A. [expands.] B. contracts. C. remains unchanged. D. Not enough information. Parts of the water will crystallize and occupy more space.
When most substances are heated, molecules inside move faster and take up more space, resulting in thermal
A. [expansion.] B. bending. C. heat. D. contraction.
When most substances are heated, molecules inside move faster and take up more space, resulting in thermal
A. [expansion.] B. contraction. C. heat. D. bending.
Thermal convection applies mainly to _________.
A. [fluids] B. radiant energy C. conductors D. insulators
When you touch a cold piece of ice with your finger, energy flows
A. [from your finger to the ice.] B. from the ice to your finger. C. actually, both ways.
The relation f ~ T tells us that high temperature sources emit electromagnetic waves of _________.
A. [high frequency] B. long wavelengths C. low frequency D. high penetrating power
A substance that heats up relatively slowly has a
A. [high specific heat capacity.] B. low specific heat capacity. C. either of these D. neither of these
Metals are good conductors of both heat and electricity due to
A. [looseness of outer electrons in metal atoms.] B. both transferring energy easily. C. relatively high densities of metals. D. similar thermal and electrical conductive properties. E. high elasticity of metals.
Ice is put in a picnic cooler. To speed up the cooling of cans of beverage, it is important that the ice
A. [melts.] B. is prevented from melting. C. be in large chunks. D. None of the above For each gram of ice that melts, 540 calories is taken from the beverage.
The fact that gasoline will overflow from an automobile tank on a hot day is evidence that the expansion of gasoline is
A. [more than the tank material.] B. about the same as the tank material. C. less than the tank material. D. negligible. Gasoline expands more with increasing temperature than its tank.
A firewalker walking barefoot across hot wooden coals depends on wood's
A. [poor conduction.] B. good conduction. C. low specific heat capacity. D. convection. Walking barefoot without burning feet on red-hot coals is due to poor conduction between coals and feet.
When a gas is changed to a liquid, the gas
A. [releases energy.] B. absorbs energy. C. both of these D. neither of these
For increased atmospheric pressure, the boiling point of water
A. [rises.] B. goes down. C. remains at 100 degrees C.
When stringing telephone lines between poles in the summer, it is advisable to allow the lines to
A. [sag.] B. be taut. C. be close to the ground. D. allow ample space for birds. Telephone lines are longer in a warmer summer and shorter in a cold winter. Hence, they sag more on hot summer days than in winter. If the lines are not strung with enough sag in summer, they might contract too much and snap during the winter—especially when carrying ice
A high-temperature source radiates relatively
A. [short wavelengths.] B. long wavelengths. C. low frequencies of radiation. D. None of these. The relation f ~ T tells us that high-temperature sources emit high-frequency waves. High-frequency waves have short wavelengths
In practice, a good insulator
A. [slows heat flow.] B. stops heat flow. C. speeds negative heat flow. D. all of the above
In practice, a good insulator
A. [slows heat flow.] B. stops heat flow. C. speeds negative heat flow. D. all of the above Insulation doesn't prevent the flow of internal energy. It slows the rate at which internal energy flows.
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 knowledge.] B. shows this knowledge is false. C. may or may not support this knowledge. D. may or may not contradict this knowledge. When placed in the coldest part of the refrigerator, the ΔT (i.e., the difference in temperature between the can and its surroundings) will be the largest, so it will cool the fastest.
When air is compressed, it generally
A. [warms.] B. cools. C. rarefies. D. expands later. Opposite to cooling by expansion. Warming occurs when air is compressed.
If bits of coals do not stick to your feet when firewalking, it's best if your feet are
A. [wet.] B. dry. C. sort of wet and sort of dry. D. None of these. The energy that vaporizes water is energy that doesn't burn your feet.
When water turns to ice, water molecules
A. absorb energy. B. [release energy.] C. retain their energy. D. lose the quality of wetness.
When steam condenses to water, energy is
A. absorbed by the steam. B. [released by the steam.] C. conserved as the phase change occurs. D. changed to a different form.
A hot pizza placed in the snow is a net
A. absorber. B. [emitter.] C. Both A and B. D. None of the above.
The inside surface of a glass window becomes wet when the temperature outside is _________.
A. almost exactly the same as on the inside B. warmer C. [colder] D. either warmer or colder
Aluminum has a higher specific heat capacity than iron. This means that for equal masses of aluminum and iron, the metal that heats more quickly when the same amount of heat is applied is
A. aluminum. B. [iron.] C. need more information
Changes of phase most always require _________.
A. an absence of molecular contact B. [transfer of energy] C. electron transfer D. condition of thermal equilibrium
When evaporation occurs in a dish of water, the molecules left behind in the water
A. are less energetic. B. have decreased average speeds. C. result in lowered temperature. D. [All of these.]
Internal energy is normally measured in units of
A. calories. B. joules. C. [Both of these.] D. None of these. Calories, calories, and joules, like miles and meters, are different units for the same thing; 1 calorie = 4.18 joules. 1 Calorie = 1000 calories = 1 kilocalorie
The surface of Earth loses energy to outer space due mostly to
A. conduction. B. convection. C. [radiation.] D. radioactivity. Radiation is the only choice, given the vacuum of outer space.
Heat can be transferred by
A. conduction. B. convection. C. radiation. D. [All of these.]
The surface of hot water has a relatively high rate of
A. convection. B. [evaporation.] C. condensation. D. conductivity.
When snow forms in clouds, the surrounding air is
A. cooled. B. [warmed.] C. insulated. D. thermally conducting. The change of phase is from gas to solid, which releases energy.
The process of boiling
A. cools the water being boiled. B. depends on atmospheric pressure. C. is a change of phase below the water surface. D. [All of the above.]
When the temperature of a strip of iron is increased, the length of the strip ___________.
A. decreases in width as it gets longer B. decreases C. may increase or decrease D. [also increases] Most substances expand when heated and contract when cooled.
The same quantity of heat is added to different amounts of water in two equal size containers. The temperature of the smaller amount of water
A. decreases more. B. [increases more.] C. does not change. D. Not enough information.
If the temperature of a sample of water at 4°C is slightly increased, its volume
A. decreases. B. remains the same. C. [increases.]
The reason that evaporation is a cooling process is
A. due to conduction and convection. B. [the more energetic molecules escape the liquid.] C. radiation of heat during the process. D. all of the above E. none of the above
Temperature is most closely related to molecular
A. electrical energy. B. [kinetic energy.] C. potential energy. D. mechanical energy in general.
Temperature is most closely related to molecular
A. electrical energy. B. potential energy. C. mechanical energy in general. D. [kinetic energy.]
The dew that forms on a cold soda can when taken from a refrigerator is due to
A. evaporation. B. [condensation.] C. sublimation. D. regelation.
When a sample of 0°C water is heated, it first
A. expands. B. [contracts.] C. remains unchanged. D. Not enough information. Water continues to contract until it reaches a temperature of 4°C. With further increase in temperature beyond 4°C, water then expands.
Condensation is a change of phase _________.
A. from liquid to gas B. without energy transfer C. from solid or liquid to gas D. [from gas to liquid]
When you touch a hot potato with your finger, energy flows
A. from your finger to the potato. B. [from the potato to your finger.] C. actually, both ways.
Energy transfer by convection is primarily restricted to
A. gases. B. [fluids.] C. liquids. D. solids. E. none of the above
The melting point of a substance such as water is normally
A. higher than the freezing point. B. lower than the freezing point. C. [the same as the freezing point.] D. unrelated to the freezing point. Water freezes at 0ºC and ice melts at 0ºC. Likewise for the melting and freezing points of other substances.
Heat energy travels from an object with a high
A. internal energy to an object with a lower internal energy. B. [temperature to an object with a lower temperature.] C. both of the above D. none of the above
To say that body A has a higher temperature than body B is to say that body A has more
A. internal energy. B. mass. C. [kinetic energy per particle.] D. potential energy.
Hot sand cools off faster at night than plants and vegetation. This indicates that the specific heat capacity for sand is ___________.
A. likely the same as that of plants B. unrelated to rate of cooling C. [less than that of plants] D. more than that of plants A substance that heats quickly has a low specific heat capacity, and a substance that cools quickly has a low specific heat capacity.
The higher the temperature of an object, the
A. longer the wavelengths it radiates. B. makes no difference in the wavelengths it radiates C. [shorter the wavelengths it radiates.]
If a good absorber of radiant energy were a poor emitter, its temperature compared with its surroundings would be
A. lower. B. [higher.] C. unaffected. D. None of the above. If a good absorber were not also a good emitter, there would be a net absorption of radiant energy, and the temperature of a good absorber would remain higher than the temperature of the surroundings. Nature is not so!
The "greenhouse gases" that contribute to global warming absorb
A. more visible radiation than infrared. B. [more infrared radiation than visible.] C. visible and infrared radiation about equally. D. very little radiation of any kind.
The molecules in a room-temperature glass of water jostle around at
A. much the same rates of speed. B. [a great variety of speeds.] C. a very small range of speeds.
Thermal convection has most to do with
A. radiant energy. B. [fluids.] C. insulators. D. All of these.
When a solid is changed to a liquid, the solid
A. releases energy. B. [absorbs energy.] C. both of these D. neither of these
When relatively slow-moving molecules condense from the air, the temperature of the remaining air tends to
A. remain unchanged. B. decrease. C. [increase.] D. spread out uniformly. Removal of slow molecules results in a greater proportion of fast ones in the air. Of course, the fastest at any moment may become the slowest with the next hit, so we speak of average molecular speeds.
If the temperature of a sample of water at 0°C is slightly increased, its volume
A. remains the same. B. increases. C. [decreases.]
When we speak about heat we refer to ___________.
A. temperature B. work C. [energy in transit] D. transfer of kinetic energy Internal energy is loosely referred to as heat energy, although by definition, heat is the energy that flows from one place to another by virtue of a temperature difference. Heat is energy in transit.
Heat is simply another word for
A. temperature. B. thermal energy. C. [internal energy that flows from hot to cold.] D. radiant energy
If a red-hot thumbtack is immersed in warm water, the direction of heat flow will be from the
A. warm water to the red-hot thumbtack. B. [red-hot thumbtack to the warm water.] C. There will be no heat flow. D. Not enough information.
When air rapidly expands, it generally
A. warms. B. [cools.] C. undergoes convection. D. radiates energy. Warm air expands, becomes less dense, is buoyed upward, and COOLS!
The temperature at which water freezes is the same as the temperature at which
A. water boils in a pressure cooker. B. [ice melts.] C. both of these D. neither of these
Evaporation is a change of phase _________.
A. without energy transfer B. from gas to liquid C. from solid or liquid to gas D. [from liquid to gas]
Which of the following normally warms up fastest when heat is applied?
A. wood B. glass C. [iron] D. water E. all of the above Iron has a lower specific heat capacity than water, wood, and glass The specific heat of iron is 0.450 J/g°C. The specific heat of water is 4.19 J/g°C.
Learning Catalytics
Temperature, Heat Transfer, Phase Changes
In Class Review
Slide Questions