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Question 12 (1 point) Question 12 Unsaved

This type of heat transfer occurs when heat moves from one molecule to another.

Question 12 options:

Radiation0


Conduction


Convection

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Question 13 (1 point) Question 13 Unsaved
What is it called when energy transfers between objects until they reach the same temperature and their particles move at the same rate?

Question 13 options:

Thermal equilibrium


Movement


Thermal energy


Kinetic Energy

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Question 14 (1 point) Question 14 Unsaved
The transfer of energy in fluids or gases is:

Question 14 options:

radiation


conduction


convection

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Question 15 (1 point) Question 15 Unsaved
What is happening between Points A-B?



Question 15 options:

Point A is demonstrating kinetic energy, as the roller coaster moves downhill the kinetic energy is transformed into potential energy.


Point A and Point B are examples of potential energy, there is not energy transformation taking place here.


Point A is demonstrating potential energy, the potential energy is then transformed into kinetic energy as the coaster moves downhill.


Point A and Point B are examples of kinetic energy, there is not energy transformation taking place here.

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Question 16 (1 point) Question 16 Unsaved
You notice after you walk across a room, you feel a spark when you touch the doorknob. What energy transformation must have taken place?

Question 16 options:

Electromagnetic -> electrical


Thermal -> electromagnetic


Electromagnetic -> mechanical


Mechanical -> electrical

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Question 17 (1 point) Question 17 Unsaved
What law states that energy can neither be created nor destroyed, but it is transformed?

Question 17 options:

Law of Thermonuclear Energy


Law of Thermal Energy


Law of Kinetic Energy


Law of Conservation of Energy

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Question 18 (1 point) Question 18 Unsaved
When you are watching TV, what is the main form of energy being used?

Question 18 options:

Mechanical


Chemical


Electrical


Nuclear

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Question 19 (1 point) Question 19 Unsaved
Which of the following energy transformations occurs when you eat a hamburger?

Question 19 options:

The chemical energy in the food is converted to mechanical energy to give the body energy to move.


The chemical energy in the food is not converted and is lost when the food is eaten.


The chemical energy in the food is converted to nuclear energy to help with digestion.


The chemical energy in the food is converted to sound energy to help the body hear.

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Question 20 (1 point) Question 20 Unsaved
The heater in your bedroom most likely uses ________________ to transfer heat.

Question 20 options:

Conduction


Radiation


Convection

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Question 21 (1 point) Question 21 Unsaved
At which two points on the pendulum, is the pendulum experiencing the greatest potential energy?



Question 21 options:

A and D


A and B


B and C


A and C

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Question 22 (1 point) Question 22 Unsaved
When a block of steel at 90 degrees Celsius is placed in a bucket of water at 30 degrees Celsius, what happens?

Question 22 options:

The temperature of the steel increases and the temperature of the water decreases.


The temperature of the steel decreases and the temperature of the water decreases.


The temperature of the steel decreases and the temperature of the water increases.


The temperature of the steel increases and the temperature of the water increases.

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Question 23 (1 point) Question 23 Unsaved
When electrical energy is "used" by an electric light, what really happens to the energy?

Question 23 options:

It stops at the electric light.


It disappears.


It is given off as other forms of energy.


It changes to matter.

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Question 24 (1 point) Question 24 Unsaved
When is kinetic energy transferred from one object to another?

Question 24 options:

When two objects are moving


When two objects are in two places


When two objects collide


When two objects pass one another

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Question 25 (1 point) Question 25 Unsaved
What energy transformation happens in a toaster?

Question 25 options:

Mechanical -> electrical


Electrical -> thermal

Thermal -> chemical


Mechanical -> thermal

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Answer 1

Heat transfer involving molecule-to-molecule contact is called conduction, energy balance between objects at the same temperature is thermal equilibrium, and energy transfer in fluids is convection. The Law of Conservation of Energy states energy can only be transformed, not created or destroyed. Electrical energy used in devices like TVs and toasters is converted into other forms of energy for operation and heating.

Step-by-step explanation:

The type of heat transfer that occurs when heat moves from one molecule to another is called conduction. It is the process of heat being transferred through stationary matter by physical contact, as experienced when cooking with a pan on a stove. When energy transfers between objects until they reach the same temperature and their particles move at the same rate, this is called thermal equilibrium.

The transfer of energy in fluids or gases is known as convection, which involves the macroscopic movement of a fluid. Between Points A and B on a roller coaster, potential energy is transformed into kinetic energy as the coaster moves downhill. When you walk across a room and feel a spark upon touching a doorknob, Mechanical -> electrical energy transformation has occurred due to the buildup and discharge of static electricity.

The principle stating that energy cannot be created or destroyed but only transformed is the Law of Conservation of Energy. When watching TV, the main form of energy being used is electrical. When you eat a hamburger, the chemical energy in the food is converted to mechanical energy to give the body the energy to move. The heater in your bedroom most likely uses convection to transfer heat. If a pendulum is at two points of greatest height, it experiences the greatest potential energy at those points.

When a block of steel at 90 degrees Celsius is placed in a bucket of water at 30 degrees Celsius, the temperature of the steel decreases and the temperature of the water increases until thermal equilibrium is reached. Electrical energy 'used' by an electric light is converted into other forms of energy such as light and thermal energy. Kinetic energy is transferred from one object to another when they collide. In a toaster, electrical energy is transformed into thermal energy to toast the bread.

Answer 2

12) Conduction. In fact, in conduction the heat is transferred when molecules collide with each other.

13) This is called thermal equilibrium. When we put two objects with different temperature in contact, their molecules have different kinetic energies. The molecules of the object with higher temperature are more energetic, and therefore they start to transfer part of their energy (by collisions) to the molecules of the object with lower temperature, until they reach a condition of equilibrium (i.e. the kinetic energies of the molecules of the two objects will be the same), and this happens when the two objects have same temperature.

14) Convection. Convection takes place in fluids: the heat is transferred by the movement of masses of fluids, from warmer regions to cooler regions.

15) Figure is missing.

16) Mechanical->Electrical. In fact, by walking through the room (movement, so mechanical energy) the body of the person acquired more electrostatic charges, and when it touches the doorknob a spark (electrical energy) takes place, because the charges accumulated on the body find a way to reach the ground throught the doorknob.

17) Law of Conservation of Energy. Indeed, it says that energy can convert into different forms, but the total energy of an isolated system must be conserved.

18) Electrical. In the cathode-ray-tube televisions, for instance, the image on the screen is produced by a current of electrons hitting the screen.

19) The chemical energy in the food is converted to mechanical energy to give the body energy to move. The energy for our body is in fact produced by the chemical reaction of the molecules of the food, and then it is used by our body to move, for instance.

20) Convection. Most of the heater uses water, which is heated and then it starts its flow to distribute the heat, therefore by convection.

21) Figure is missing.

22) The temperature of the steel decreases and the temperature of the water increases. In fact, as we said in number 13), the steel will transfer part of its energy to the water until they reach thermal equilibrium, so the temperature of the steel will decrease while the temperature of the water will increase.

23) It is given off as other forms of energy. In particular, it is converted into radiant energy: the bulb emits light, which is electromagnetic radiation, so the energy is re-emitted as radiation.

24) When two objects collide. For instance, assuming there is a body moving with speed v and another body stationary (with same mass), when they collide the first body transfers its kinetic energy to the second body, putting it in motion.

25) Electrical -> thermal. In a toaster, there is a resistance through which current flows. Due to the Joule effect, the current flowing through the resistor causes an increase of temperature of the resistor itself, therefore the energy of the current (electrical) is converted into thermal energy, which is then used to heat the toast.