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energy Flashcards

(65 cards)

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1
Q

What is energy?

A

The ability to do work or produce change.

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2
Q

What are the two main types of energy?

A

Kinetic energy and potential energy.

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3
Q

Define kinetic energy.

A

The energy an object possesses due to its motion.

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4
Q

What is the formula for kinetic energy?

A

KE = 1/2 mv², where m is mass and v is velocity.

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5
Q

Define potential energy.

A

The energy stored in an object due to its position or arrangement.

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6
Q

What is gravitational potential energy?

A

Potential energy related to an object’s height above the ground.

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7
Q

What is the formula for gravitational potential energy?

A

PE = mgh, where m is mass, g is the acceleration due to gravity, and h is height.

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8
Q

True or False: Energy can be created and destroyed.

A

False; energy cannot be created or destroyed, only transformed.

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9
Q

What is the law of conservation of energy?

A

Energy cannot be created or destroyed, only converted from one form to another.

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10
Q

Fill in the blank: The total energy in a closed system _______.

A

remains constant.

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11
Q

What is thermal energy?

A

The total kinetic energy of particles in an object due to their motion.

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12
Q

What is the unit of energy?

A

Joule (J).

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13
Q

Define work in terms of energy.

A

Work is the process of energy transfer when a force is applied to an object.

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14
Q

What is the formula for work?

A

W = Fd, where F is force and d is distance.

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15
Q

What is power?

A

The rate at which work is done or energy is transferred.

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16
Q

What is the formula for power?

A

P = W/t, where W is work and t is time.

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17
Q

What is the unit of power?

A

Watt (W).

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18
Q

True or False: 1 Watt is equal to 1 Joule per second.

A

True.

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19
Q

What is mechanical energy?

A

The sum of kinetic and potential energy in a system.

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20
Q

What is a renewable energy source?

A

Energy that can be replenished naturally, such as solar or wind energy.

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21
Q

What is a non-renewable energy source?

A

Energy that cannot be replenished in a short time, such as fossil fuels.

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22
Q

What is solar energy?

A

Energy from the sun that can be converted into electricity or heat.

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23
Q

What is wind energy?

A

Energy obtained from the wind using turbines to generate electricity.

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24
Q

What is fossil fuel?

A

Natural fuels formed from the remains of ancient plants and animals, such as coal, oil, and natural gas.

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25
What is nuclear energy?
Energy released during nuclear fission or fusion.
26
What is energy efficiency?
The ratio of useful energy output to total energy input.
27
How can energy be conserved at home?
By using energy-efficient appliances and reducing unnecessary energy use.
28
What is the greenhouse effect?
The warming of Earth's surface due to trapped heat by greenhouse gases.
29
What are greenhouse gases?
Gases that trap heat in the atmosphere, such as carbon dioxide and methane.
30
What is biomass energy?
Energy produced from organic materials, such as plants and animal waste.
31
What is geothermal energy?
Energy derived from the heat stored beneath the Earth's surface.
32
What does 'energy transformation' mean?
The process of changing energy from one form to another.
33
Fill in the blank: In a pendulum, energy transforms between ______ and ______ energy.
kinetic; potential.
34
What is a closed system?
A physical system that does not exchange matter with its surroundings.
35
What is an open system?
A system that can exchange both energy and matter with its surroundings.
36
What is a system's energy store?
The way energy is held within a system, such as in kinetic, potential, or thermal forms.
37
What is energy transfer?
The movement of energy from one location or object to another.
38
What is conduction?
The transfer of thermal energy through direct contact between materials.
39
What is convection?
The transfer of thermal energy through the movement of fluids.
40
What is radiation?
The transfer of energy through electromagnetic waves.
41
True or False: Heat always flows from a cooler object to a warmer object.
False; heat flows from warmer to cooler objects.
42
What is the efficiency of a machine?
The percentage of input energy that is converted to useful output energy.
43
What is the formula for efficiency?
Efficiency = (Useful energy output / Total energy input) x 100.
44
What does a Sankey diagram represent?
The flow of energy in a system, showing energy inputs, useful outputs, and wasted energy.
45
What is energy audit?
An assessment of energy use in a building to identify opportunities for energy savings.
46
What is a carbon footprint?
The total amount of greenhouse gases emitted by an individual, organization, or product.
47
What is the impact of fossil fuels on the environment?
They contribute to air pollution and climate change due to greenhouse gas emissions.
48
What is hydroelectric power?
Electricity generated by using the energy of flowing water.
49
What is tidal energy?
Energy generated from the movement of tides.
50
What is wave energy?
Energy harnessed from the surface motion of ocean waves.
51
What is the purpose of insulation?
To reduce heat loss from buildings, improving energy efficiency.
52
What does 'smart grid' refer to?
An electricity supply network that uses digital technology to monitor and manage energy flows.
53
What is carbon capture?
A technology that captures carbon dioxide emissions from sources like power plants.
54
What are the benefits of renewable energy?
Reduced greenhouse gas emissions, sustainable energy sources, and energy security.
55
What is a photovoltaic cell?
A device that converts sunlight directly into electricity.
56
What is energy storage?
The capture of energy produced at one time for use at a later time.
57
What is the principle of a heat pump?
To transfer heat from a cooler area to a warmer area using mechanical work.
58
What is the difference between renewable and non-renewable resources?
Renewable resources can be replenished naturally, while non-renewable resources cannot.
59
What is energy security?
The uninterrupted availability of energy sources at an affordable price.
60
What is the role of government in energy policy?
To regulate energy markets, promote renewable energy, and ensure energy security.
61
What is a sustainable energy source?
An energy source that meets present needs without compromising future generations.
62
What does 'energy transition' refer to?
The global energy sector's shift from fossil-based systems to renewable energy sources.
63
What is the importance of energy in society?
Energy powers homes, industries, transportation, and is essential for economic development.
64
What is energy poverty?
The lack of access to modern energy services, affecting quality of life and economic opportunities.
65
What is the impact of energy consumption on climate change?
Increased energy consumption from fossil fuels leads to higher greenhouse gas emissions.

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