Q&A Hero

Q: Thermal energy will flow in a direction from cold to hot A) only with external effort. B) near absolute zero. C) never. D) always.

Q: Heat is thermal energy that matter A) contains. B) transfers. C) both of these D) none of the above

Q: Heat is thermal energy that flows from A) hot to cold. B) high energy to low energy. C) high thermal pressure to low thermal pressure. D) all of the above

Q: Heat is thermal energy that flows due to A) molecular speed. B) calorie imbalance. C) temperature differences.

Q: When you touch a hot penny in the sunlight with your finger, energy flows A) from your finger to the penny. B) from the penny to your finger. C) both ways.

Q: When you touch a piece of ice with your finger, energy flows A) from your finger to the ice. B) from the ice to your finger. C) both of these D) none of the above

Q: Heat energy is measured in units of A) degrees. B) joules. C) calories. D) both joules and calories.

Q: Heat is A) temperature. B) thermal energy. C) thermal energy flowing from hot to cold. D) radiant energy.

Q: Heat is simply another word for A) temperature. B) thermal energy. C) both of these D) none of the above

Q: A volume of helium gas has a temperature of 10C. The same gas twice as hot has a temperature of A) 20C. B) 12C. C) 283C. D) 293C. E) none of the above

Q: A volume of helium gas has a temperature of 0C. The same gas twice as hot has a temperature of A) 0C. B) 2C. C) 100C. D) 273C. E) none of the above

Q: When a gas such as helium becomes twice as hot it has A) twice the thermal energy. B) twice the absolute temperature. C) both of these D) none of the above

Q: At absolute zero, a substance has A) absolutely no molecular motion. B) no more energy to give up. C) no volume. D) all of the above

Q: The temperature at the center of the Sun is about 107 degrees. Does it matter whether this is stated as Celsius degrees or kelvins? A) yes, the kelvin rating will be appreciably higher B) yes, the kelvin rating will be appreciably lower C) no, they are practically the same

Q: When the temperature of a fixed volume of air initially at 0 C is lowered by 1 degree, its pressure A) decreases by 1/273. B) decreases by 100/273. C) increases by 1/273. D) increases by 100/273.

Q: When the temperature of a quantity of 0-C air at constant pressure is lowered by 1 degree, its volume A) shrinks by 1/273. B) shrinks by 100/273. C) increases by 1/273. D) increases by 100/273.

Q: Room temperature on the Kelvin scale is about A) 100 K. B) 200 K. C) 300 K. D) 400 K. E) more than 400 K.

Q: A temperature difference of 10 Celsius degrees is also equal to a temperature difference of 10 on the A) Fahrenheit scale. B) Kelvin scale. C) both of these D) neither of these

Q: The lowest possible temperature is A) 0C. B) -273C. C) 4 K.

Q: Absolute zero corresponds to a temperature of A) 0 K. B) -273 C. C) both of these D) none of the above

Q: Which of these is the smallest? A) 1 Celsius degree B) 1 kelvin C) 1 Fahrenheit degree D) all are the same

Q: The fact that a thermometer "takes its own temperature" illustrates A) thermal equilibrium. B) energy conservation. C) the difference between heat and thermal energy. D) that molecules are constantly moving.

Q: Which temperature scale has the smallest sized degrees? A) Fahrenheit B) Celsius C) Kelvin D) none of the above

Q: On which temperature scale is 212 degrees the boiling point of water? A) Celsius B) Caloric C) Kelvin D) Fahrenheit E) none of the above

Q: On which temperature scale is 0 degrees the freezing point of water? A) Celsius B) Caloric C) Kelvin D) Fahrenheit E) none of the above

Q: The temperature of melting ice is A) 0C. B) 32F. C) both of these

Q: The temperature of boiling water is A) 100C. B) 212F. C) both of these

Q: The motion of particles that contribute to thermal energy are A) translational. B) rotational. C) vibrational. D) all of the above

Q: The motion of atoms and molecules that most affects temperature is A) translational. B) rotational. C) vibrational. D) none of the above

Q: Whether one object is warmer than another object has most to do with molecular A) kinetic energy. B) potential energy. C) masses.

Q: Explain why fish are able to survive through cold winters even when the ponds are frozen over.

Q: If water had a lower specific heat capacity, would ponds and lakes be more or less likely to freeze in winter?

Q: Helium gas has the special property that its thermal energy is directly proportional to its Kelvin temperature. Consider a flask of helium with a temperature of 10C. If it is heated until it has twice as much thermal energy, show that its temperature is 293C. Why would doubling the thermal energy of a flask of 10C water not produce the same temperature?

Q: Distinguish between the concepts of thermal energy, temperature, and heat.

Q: Explain what is meant by saying a thermometer measures its own temperature.

Q: The rise in ocean levels is due to A) warmer water. B) melting of ice on land that flows into the ocean. C) both of these D) none of the above

Q: When ice that floats in water melts, the surrounding water level A) falls. B) remains unchanged. C) rises.

Q: When ice floats in water, a small part of it extends above the surface. Interestingly, the volume of ice that extends above the surface is equal to the volume of the A) water the ice displaces. B) vast number of open spaces in the hexagonal ice crystals. C) both of these D) none of the above

Q: The temperature at the bottom of Lake Tahoe, high in the Sierra Mountains in California, at this moment is A) below 4C. B) 4C. C) above 4C. D) uncertain.

Q: Ice tends to form at the A) surface of bodies of water. B) layer of water slightly below the surface. C) bottom of bodies of water.

Q: Before ice can form on a lake, all the water in the lake must be cooled to A) 0C. B) 4C. C) a value slightly below 0C.

Q: Ice has a lower density than water because ice A) sinks. B) molecules are more compact in the solid state. C) molecules vibrate at lower rates than water molecules. D) is composed of open-structured crystals. E) density decreases with decreasing temperature.

Q: Water at 4C will sink to the bottom of a pond because A) it will not freeze there. B) it benefits fish and other life forms there. C) like a rock, it is denser than surrounding water. D) of the presence of microscopic ice crystals.

Q: The density of water at 4C will slightly decrease when it is A) cooled. B) warmed. C) both of these D) none of the above

Q: The greatest expansion of water among the following occurs when A) it turns to ice. B) at 4C it gains thermal energy. C) at 4C it loses thermal energy. D) none of the above

Q: Microscopic slush in water tends to make the water A) more dense. B) less dense. C) slipperier. D) warmer.

Q: Which expands more when the temperature is lowered? Equal volumes of A) iron. B) wood. C) helium. D) water at 4C. E) none expand when the temperature is lowered

Q: Water at 4C will contract when it is slightly A) cooled. B) warmed. C) both of these D) none of the above

Q: Water at 4C will expand when it is slightly A) cooled. B) warmed. C) both of these D) none of the above

Q: If water at 4C slightly decreases in temperature, the water A) contracts. B) expands. C) neither of these

Q: If water at 4C slightly increases in temperature, the water A) contracts. B) expands. C) neither of these

Q: If water at 0C slightly increases in temperature, the water A) contracts. B) expands. C) neither of these

Q: If water at 20C slightly increases in temperature, the water A) expands. B) contracts. C) remains the same.

Q: The open spaces in the crystal lattice of ice contain A) vapor. B) trace amounts of water. C) nothing.

Q: The overflow of gasoline from a car's full metal tank on a hot day is evidence that gasoline expands A) more than metal. B) about the same as metal. C) less than metal. D) none of the above.

Q: During a very cold winter, water pipes sometimes burst because A) the ground contracts when colder, pulling pipes apart. B) water expands when freezing. C) water contracts when freezing. D) the thawing process produces pressure on the pipes. E) none of the above

Q: When a metal ring with a gap in the shape of the letter C is cooled, the gap becomes A) wider. B) narrower. C) remains the same size.

Q: When a metal ring with a gap in the shape of the letter C is heated, the gap becomes A) wider. B) narrower. C) remains the same size.

Q: As a hot iron ring cools, the diameter of the hole A) increases. B) decreases. C) remains the same.

Q: When an iron ring is heated, the hole becomes A) smaller. B) larger. C) neither

Q: If glass expanded more than mercury in a thermometer, then with rising temperature the column of mercury would A) rise. B) not change. C) fall.

Q: A pre-electronic thermostat employs a coiled A) wire of low conductivity. B) bimetallic strip. C) tube of mercury.

Q: When a bimetallic bar of copper and iron strips is heated, the bar bends toward the iron strip because A) iron gets hotter before copper. B) copper gets hotter before iron. C) copper expands more than iron. D) iron expands more than copper. E) none of the above

Q: The operation of a bimetallic strip relies on differences in A) expansions of metals. B) conductivities of metals. C) heat capacities of metals.

Q: Which contracts more when the temperature is slightly increased? Equal volumes of A) iron. B) wood. C) ice water. D) helium. E) none of the above contract when heated

Q: Which contracts more when the temperature is decreased? Equal volumes of A) iron. B) wood. C) water. D) helium. E) all contract the same

Q: Which expands more when the temperature is increased? Equal volumes of A) iron. B) wood. C) ice water. D) helium. E) all expand the same

Q: When most substances are heated, molecules inside move faster and occupy more space, which results in thermal A) bending. B) expansion. C) contraction. D) heat.

Q: A kg of 40C water and a kg of 20C water, after being mixed, have a temperature of 30C. However, the final temperature of a 1-kg iron block at 40C placed into 1 kg of water at 20C is A) less than 30C. B) at or about 30C. C) more than 30C.

Q: Materials composed of molecules that absorb large amounts of energy in the form of vibrations and rotations have A) low specific heat capacities. B) high specific heat capacities. C) none of the above

Q: If the specific heat capacity of water were lower, ponds in the cold winter would be A) more likely to freeze. B) less likely to freeze. C) neither more nor less likely to freeze.

Q: The specific heat capacity of aluminum is more than twice that of copper. Place equal masses of aluminum and copper wire in a flame and the wire to heat up quickest will be A) copper. B) aluminum. C) both the same

Q: Hot sand cools off faster at night than plants and vegetation, which indicates that the specific heat capacity of sand is A) less than for plants. B) more than for plants. C) likely the same as for plants. D) not enough information

Q: The fact that desert sand becomes very hot in the day and very cold at night is evidence that sand has a A) low specific heat capacity. B) high specific heat capacity. C) none of the above

Q: San Francisco has milder winters than Washington D.C. due to water's high A) conductivity. B) specific heat capacity. C) temperature in the Pacific Ocean.

Q: The moderate temperatures of islands throughout the world has mainly to do with water's A) poor conductivity. B) vast supply of thermal energy. C) high specific heat capacity. D) high evaporation rate. E) absorption of solar energy.

Q: Which will stay cooler for a longer time in a picnic cooler on a hot summer day? A) sandwiches B) salami C) Jello

Q: Which will cool faster when removed from a furnace? A) iron B) silver C) the same

Q: Which of the following normally warms up faster when heat is applied? A) water B) iron C) glass D) wood

Q: Which has the greater specific heat capacity; the filling of a hot piece of pie or the crust? A) the filling B) the crust C) depends on the temperature