1.
Rising warm air currents is an example of
Correct Answer
C. Convection
Explanation
Convection is the transfer of heat through the movement of a fluid, such as air or water. Rising warm air currents is an example of convection because the warm air rises due to its lower density compared to the surrounding cooler air. As the warm air rises, it transfers heat to the cooler air, creating a convection current. This process is commonly observed in weather phenomena such as the formation of thunderstorms and the circulation of air in a room when a heater is turned on.
2.
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, which in turn warms the air through a process called conduction. The warm air then rises and creates convection currents, which distribute heat throughout the atmosphere.
3.
True or False higher temperature means faster moving molecules
Correct Answer
A. True
Explanation
Higher temperature means that the average kinetic energy of the molecules in a substance is higher. Since kinetic energy is directly proportional to the speed of the molecules, higher temperature leads to faster moving molecules. Therefore, the statement "higher temperature means faster moving molecules" is true.
4.
The reason why water boils causing the circular motion is due to?
Correct Answer
C. Convection
Explanation
Water boils causing 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, it becomes less dense and rises to the top while the cooler, denser water sinks to the bottom. This creates a circular motion as the hot water rises and the cool water sinks, causing the water to boil.
5.
When you get into a car with hot black leather in the middle of the summer and you burn your legs, this is an example of?
Correct Answer
B. Conduction
Explanation
When you get into a car with hot black leather in the middle of the summer and you burn your legs, this is an example of conduction. Conduction is the transfer of heat through direct contact between two objects or substances. In this case, the heat from the hot black leather is transferred to your legs through direct contact, causing them to burn.
6.
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 through electromagnetic waves, such as sunlight. In this case, the rocks absorb the energy from the sun's rays, causing them to heat up. Conduction and convection, on the other hand, involve the transfer of heat through direct contact or the movement of fluids, respectively, and are not applicable in this scenario.
7.
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 with a temperature of 20oC is placed into a cup of water with a temperature of 90oC, the heat is transferred from the hotter object (water) to the cooler object (spoon) through direct contact. This process is known as conduction. The molecules in the spoon gain kinetic energy from the water molecules, causing the spoon to heat up.
8.
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, creating a flow of heat and gases. The cooler air near the floor replaces the rising hot air, resulting in a continuous cycle of upward movement. This process is known as convection, where heat is transferred through the movement of fluids or gases. In this case, the movement of hot air and smoke is the result of convection.
9.
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 one molecule to another by means of molecular collisions. This is different from radiation, where heat is transferred through electromagnetic waves, and convection, where heat is transferred through the movement of a fluid.
10.
When heat is given off by light this type of heat is known as?
Correct Answer
A. Radiation
Explanation
Heat given off by light is known as radiation. Radiation is the transfer of heat through electromagnetic waves, such as infrared radiation. This type of heat transfer does not require a medium and can occur through empty space.
11.
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. In this process, heat energy is transferred from the hotter substance to the colder substance through direct molecular interaction. Unlike radiation and convection, which involve the transfer of heat through different mediums or through the movement of fluids, conduction occurs solely through direct contact. Therefore, conduction is the correct answer for the given question.
12.
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 energy through electromagnetic waves. In the picture, the rays are shown emanating from a central source, indicating the emission of heat 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 the movement of particles in a fluid medium, respectively.
13.
Correct Answer
B. Convection
14.
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 the heated air rises, cooler air from the surrounding environment moves in to take its place. This circulation of air due to the difference in temperature is known as convection.
15.
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. In this scenario, the hot street is in direct contact with your bare feet, causing the heat to transfer from the street to your toes through conduction.
16.
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 a campfire feeling warm even though he is 10 feet away suggests that the heat is reaching him through radiation. Radiation is the transfer of heat through electromagnetic waves, such as infrared radiation, which can travel through empty space. In this case, the campfire emits heat in the form of radiation, and the boy is able to feel the warmth from the fire even though he is not in direct contact with it.
17.
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 particles. When a fluid or gas is heated, the particles gain energy and move faster, causing them to spread out and become less dense. This leads to the hotter fluid or gas rising and the cooler fluid or gas sinking, creating a circular motion known as convection currents. Through these currents, heat is transferred from the hotter regions to the cooler regions of the fluid or gas. Therefore, convection is the appropriate term for the transfer of energy in fluids or gases.
18.
Light waves traveling through empty space
Correct Answer
C. Radiation
Explanation
Light waves traveling through empty space is an example of radiation. Radiation refers to the transfer of energy through electromagnetic waves, such as light, without the need for a medium. In this case, the light waves are able to propagate and travel through empty space, demonstrating the process of radiation.