1.
Which one is a form of heat transfer.
Correct Answer
A. Conduction
Explanation
Conduction is a form of heat transfer where heat is transferred through direct contact between particles or objects. In this process, heat energy is transferred from the hotter object to the cooler object through molecular collisions. Unlike absorption, refraction, and reflection, which are not forms of heat transfer, conduction involves the flow of heat from one object to another without the need for any medium or radiation.
2.
Conduction uses ___________ contact.
Correct Answer
direct
Explanation
Conduction uses direct contact because it involves the transfer of heat or electricity through direct physical contact between two objects. In this process, the heat or electricity flows from a region of higher temperature or voltage to a region of lower temperature or voltage through the direct contact between the objects. This direct contact allows for the efficient transfer of energy between the objects.
3.
What type of heat transfer is the sun?
Correct Answer
B. Radiation
Explanation
The sun is an example of radiation as a type of heat transfer. Radiation is the process of transferring heat through electromagnetic waves without the need for a medium. In the case of the sun, it emits heat and light in the form of electromagnetic waves, which travel through space and reach the Earth. This is how the sun's heat reaches us without the need for any direct contact or medium in between. Convection, on the other hand, involves the transfer of heat through the movement of fluids, while conduction refers to the transfer of heat through direct contact between objects.
4.
What type of heat transfer is mainly seen with solids?
Correct Answer
B. Conduction
Explanation
Conduction is the main type of heat transfer observed in solids. Conduction occurs when heat is transferred through direct contact between particles within a solid material. In solids, the particles are closely packed together, allowing for efficient transfer of heat energy from higher temperature regions to lower temperature regions. Unlike convection, which involves the movement of fluids, and radiation, which occurs through electromagnetic waves, conduction is the most dominant form of heat transfer in solids.
5.
__________ travels in waves.
Correct Answer
Radiation
Explanation
Radiation travels in waves because it is a form of energy that is transmitted through space or a medium in the form of electromagnetic waves or particles. These waves can have various frequencies and wavelengths, and they can travel through vacuum or matter. Examples of radiation include visible light, radio waves, X-rays, and gamma rays.
6.
Rising warm air currents is an example of
Correct Answer
C. Convection
Explanation
Convection is the transfer of heat through the movement of fluids (liquids or gases). Rising warm air currents are a perfect example of convection because as warm air rises, it displaces cooler air, creating a continuous circulation of heat. This process is commonly observed in weather patterns, where warm air rises from the Earth's surface, cools down at higher altitudes, and then descends back to the surface. Convection is an important mechanism for heat transfer in various natural phenomena, such as ocean currents and the formation of thunderstorms.
7.
A thermometer works because the liquid in it contracts when heated this is an example of
Correct Answer
C. Convection
Explanation
A thermometer works by measuring the expansion or contraction of a liquid, typically mercury or alcohol, in response to changes in temperature. In the case of a mercury thermometer, when the temperature increases, the liquid mercury expands and rises up the narrow tube, indicating a higher temperature. This expansion and contraction of the liquid is an example of convection, as heat is transferred through the movement of the liquid particles. Conduction refers to the transfer of heat through direct contact, while radiation is the transfer of heat through electromagnetic waves.
8.
How is air heated in our atmosphere
Correct Answer
C. Convection
Explanation
Air is heated in our atmosphere through the process of convection. Convection occurs when warmer air rises and cooler air sinks. As the sun heats the Earth's surface, the air in contact with the surface becomes warmer and less dense. This warm air then rises, creating a convection current. As the warm air rises, it transfers its heat to the cooler air around it. This process continues, causing the air to circulate and distribute heat throughout the atmosphere. Therefore, convection is the primary mechanism by which air is heated in our atmosphere.
9.
True or False the sun DIRECTLY heats the air in our atmosphere
Correct Answer
B. False
Explanation
False. The sun does not directly heat the air in our atmosphere. Instead, it heats the Earth's surface, and then the surface transfers heat to the air through conduction and convection. This process causes the air to warm up and creates temperature variations in the atmosphere.
10.
True or False higher temperature means faster moving molecules
Correct Answer
A. True
Explanation
Higher temperature means faster moving molecules because temperature is a measure of the average kinetic energy of the particles in a substance. When the temperature increases, the particles gain more kinetic energy, causing them to move faster. This is because the increase in temperature leads to an increase in the speed and frequency of molecular collisions. As a result, the molecules move more rapidly and have a higher average velocity. Therefore, it is true that higher temperature corresponds to faster moving molecules.
11.
True or false - air is a great conductor of heat
Correct Answer
B. False
Explanation
Air is not a great conductor of heat because it is a poor conductor of thermal energy. Unlike metals or other materials, air has low density and low thermal conductivity, meaning it does not transfer heat efficiently. This is why insulating materials, such as air-filled gaps or layers of air, are commonly used to reduce heat transfer in buildings and other applications.
12.
The reason why water boils causing the circular motion is due to?
Correct Answer
C. Convection
Explanation
Water boils and causes circular motion due to convection. Convection is the transfer of heat through the movement of a fluid, in this case, water. When water is heated, the molecules gain energy and move faster, causing them to spread out and become less dense. The less dense hot water rises to the top, while the denser cold water sinks to the bottom. This creates a circular motion, known as convection currents, as the hot water continuously rises and the cold water continuously sinks. Therefore, convection is the reason why water boils and causes circular motion.
13.
When rocks are heated by the warmth of the sun this is an example of?
Correct Answer
A. Radiation
Explanation
When rocks are heated by the warmth of the sun, it is an example of radiation. Radiation is the transfer of heat energy through electromagnetic waves, such as infrared radiation from the sun. In this case, the rocks absorb the heat energy radiated by the sun, causing them to increase in temperature. Conduction and convection, on the other hand, involve the transfer of heat through direct contact or movement of particles respectively, which are not applicable in this scenario.
14.
When a metal spoon with a temperature of 20oC is placed into a cup of water with a temperature of 90oC the spoon will heat up. This is an example of:
Correct Answer
B. Conduction
Explanation
When a metal spoon is placed into a cup of hot water, the heat is transferred from the water to the spoon through direct contact. This process is known as conduction. The molecules in the hot water collide with the molecules in the spoon, transferring their kinetic energy and causing the spoon to heat up. This is different from radiation, which involves the transfer of heat through electromagnetic waves, and convection, which involves the transfer of heat through the movement of fluids.
15.
During a house fire, the smoke and flames rise up, but the air down near the floor is cooler and less smoky. This is an example of
Correct Answer
C. Convection
Explanation
During a house fire, convection occurs as the hot air and smoke rise upwards while the cooler air near the floor moves in to replace it. This is because hot air is less dense and therefore rises, creating a convection current. Convection is the transfer of heat through the movement of a fluid, in this case, air.
16.
This type of heat transfer occurs when heat moves from one molecule to another.
Correct Answer
B. Conduction
Explanation
Conduction is the correct answer because it refers to the transfer of heat between molecules through direct contact. In this process, heat energy is transferred from the higher temperature molecules to the lower temperature ones. Unlike convection and radiation, conduction does not involve the movement of molecules or the use of a medium for heat transfer. Instead, it relies on the collision and transfer of thermal energy between adjacent molecules.
17.
When heat is given off by light this type of heat is known as?
Correct Answer
A. Radiation
Explanation
When heat is given off by light, it is known as radiation. Radiation is the transfer of heat energy through electromagnetic waves, such as infrared radiation. Unlike conduction and convection, which require a medium (solid, liquid, or gas) for heat transfer, radiation can occur in a vacuum as well.
18.
The transfer of heat between substances that are in direct contact with each other is called what?
Correct Answer
C. Conduction
Explanation
Conduction is the transfer of heat between substances that are in direct contact with each other. It occurs when heat is transferred from a hotter object to a cooler object through direct molecular collision. Unlike convection, which involves the movement of fluids, and radiation, which involves the transfer of heat through electromagnetic waves, conduction specifically refers to the transfer of heat through direct contact.
19.
The rays in this picture is an example of
Correct Answer
C. Radiation
Explanation
The rays in the picture are an example of radiation because radiation is the transfer of heat through electromagnetic waves, such as light or infrared radiation. In the picture, the rays appear to be emanating from a source, indicating the release of energy in the form of electromagnetic waves. This is characteristic of radiation, where heat is transferred without the need for a medium or direct contact between objects. Conduction and convection, on the other hand, involve the transfer of heat through direct contact or movement of a medium, respectively.
20.
Correct Answer
B. Convection
21.
The air in the hot air balloon is heated and circulates. This is an example of ...
Correct Answer
B. Convection
Explanation
The air in the hot air balloon is heated, causing it to become less dense and rise. As it rises, cooler air from the surroundings replaces the hot air, creating a circulation of air within the balloon. This process, known as convection, is the transfer of heat through the movement of a fluid (in this case, air).
22.
You walk barefoot on the hot street and it burns your toes. This is an example of...
Correct Answer
A. Conduction
Explanation
Conduction is the transfer of heat through direct contact between two objects or substances. In this scenario, the hot street is in direct contact with the person's bare feet, causing the heat to transfer from the street to the feet through conduction.
23.
A boy sits to the side of a campfire. He is 10 feet away, but still feels warm. This is an example of ...
Correct Answer
C. Radiation
Explanation
The boy sitting to the side of the campfire feels warm even though he is 10 feet away because of radiation. Radiation is the transfer of heat through electromagnetic waves. In this case, the campfire emits thermal radiation in the form of infrared waves, which travel through the air and reach the boy, causing him to feel warm. Conduction and convection involve the transfer of heat through direct contact or movement of a medium, respectively, and are not applicable in this scenario.
24.
The transfer of energy in fluids or gases.
Correct Answer
B. Convection
Explanation
Convection is the transfer of energy in fluids or gases through the movement of the particles within the substance. This movement occurs due to temperature differences, where the warmer particles rise and the cooler particles sink, creating a circular motion. This process allows for the transfer of heat or energy from one part of the fluid or gas to another. Therefore, convection is the most appropriate answer for the given question.
25.
Light waves traveling through empty space.
Correct Answer
C. Radiation
Explanation
Radiation is the process by which energy is transferred through electromagnetic waves, such as light waves, traveling through empty space. Unlike conduction and convection, which require a medium such as a solid or a fluid, radiation can occur in a vacuum. Therefore, in the given context, light waves traveling through empty space can only be explained by radiation.
26.
Which three of these choices are ways of heat transfer?
Correct Answer(s)
A. Radiation
C. Conduction
E. Convection
Explanation
Radiation, conduction, and convection are all methods of heat transfer. Radiation refers to the transfer of heat through electromagnetic waves, such as from the sun to the Earth. Conduction is the transfer of heat through direct contact between two objects or substances. Convection is the transfer of heat through the movement of fluids or gases, such as the circulation of warm air in a room. Ultraviolet and refraction are not methods of heat transfer, but rather refer to different aspects of light and its behavior.
27.
Which of these are good conductors?
Correct Answer(s)
B. Iron
D. Steel
E. Copper
Explanation
Iron, steel, and copper are good conductors of electricity and heat. They have a high density of free electrons that can move easily through the material, allowing for the efficient flow of electric current. Wood and plastic, on the other hand, are insulators and do not allow the flow of electricity.
28.
Which of these are good insulators?
Correct Answer(s)
A. Blanket
B. Mitten
E. Coat
Explanation
Blanket, mitten, and coat are good insulators because they are made of materials that can trap air and prevent heat transfer. These materials have low thermal conductivity, meaning they do not easily allow heat to flow through them. This property helps to keep the body warm by reducing heat loss to the surroundings. In contrast, metal and paper have high thermal conductivity and would allow heat to easily pass through them, making them poor insulators.
29.
The thermal energy that flows from something at a higher temperature to something at a lower temperature. Name which definition this is matches to.
Correct Answer
C. Heat
Explanation
The given definition matches with the term "heat." Heat refers to the thermal energy that flows from something at a higher temperature to something at a lower temperature.
30.
The sum of kinetic and potential energy of all the particles in an object. Name which definition this matches to.
Correct Answer
E. None of the above
Explanation
The definition belongs to the words Thermal Energy.
31.
____________ is the measure f the average kinetic energy of the particles in the object.
Correct Answer
Temperature
Explanation
Temperature is the measure of the average kinetic energy of the particles in an object. It indicates how fast the particles are moving and the amount of energy they possess. When the temperature is high, it means that the particles have a higher average kinetic energy and are moving faster. Conversely, when the temperature is low, the particles have a lower average kinetic energy and are moving slower. Therefore, temperature is a measure of the thermal energy or heat present in an object.
32.
Radiation can come from:
Correct Answer
E. The Sun
Explanation
Radiation can come from various sources, including Britney Spears, a chocolate bar, a broken lightbulb, a wall, and the Sun. However, the Sun is a major natural source of radiation. It emits a wide range of electromagnetic radiation, including visible light, ultraviolet (UV) radiation, and even some X-rays and gamma rays. These forms of radiation are essential for life on Earth but can also be harmful in excessive amounts. Therefore, the Sun is the correct answer as it is a significant and well-known source of radiation.
33.
Things contract when heated because molecules move more
Correct Answer
B. False
Explanation
When materials are heated, the molecules within them gain energy and move more rapidly. This increased movement causes the molecules to spread out and occupy a larger volume, resulting in expansion rather than contraction. Therefore, the statement that things contract when heated is incorrect, making the answer False.
34.
Heat flows hot to cold.
Correct Answer
A. True
Explanation
Heat flows from hot to cold because of the second law of thermodynamics, which states that heat naturally flows in the direction of decreasing temperature. This is due to the fact that molecules in a hotter object have higher kinetic energy and move more rapidly, colliding with the molecules in a colder object and transferring energy to them. As a result, the hotter object cools down and the colder object heats up until they reach thermal equilibrium. Therefore, heat always moves from the hotter object to the colder object.