Energy: Forms And Uses Flashcards
(113 cards)
1
Q
What is energy?
A
Energy is the ABILITY to do WORK.
2
Q
From what sources do we get our energy?
A
We get our energy from many sources such as food, fossil fuels, and others.
3
Q
What can energy cause?
A
Energy can cause things to move or change in state.
4
Q
What are examples of different forms of energy?
A
- Heat energy
- Light energy
- Electrical energy
- Kinetic energy
- Potential energy
- Sound energy
5
Q
Why do we need energy?
A
We need energy to stay alive. All parts of our body need energy to function.
6
Q
How do we obtain energy for our bodily functions?
A
We get this energy from the food we eat.
7
Q
What happens to energy when we use it?
A
Energy is neither created nor destroyed. It changes from one form of energy into another.
8
Q
List forms of energy.
A
- Electrical energy
- Light energy
- Heat energy
- Sound energy
- Kinetic energy
- Potential energy
9
Q
What is kinetic energy?
A
Kinetic energy is the energy of motion.
10
Q
What is potential energy?
A
Potential energy is stored energy based on position or state.
11
Q
True or False: Energy can be created and destroyed.
A
False
12
Q
Fill in the blank: Energy is _______.
A
[the ability to do work]
13
Q
What form of energy is associated with sound?
A
Sound energy
14
Q
What is the relationship between energy and movement?
A
Energy can cause things to move.
15
Q
What is light energy?
A
Light energy is a form of energy that is visible to the human eye.
16
Q
What is heat energy?
A
Heat energy is the energy that comes from the temperature of matter.
17
Q
What is light energy?
A
Light energy is a form of energy that enables us to see.
18
Q
How do plants use light energy?
A
Light energy from the Sun enables plants with chlorophyll to make food.
19
Q
How do we see objects?
A
Objects can be seen if they give off light or if they reflect light.
20
Q
What are some uses of light energy?
A
Light energy has many uses, including in cameras, projectors, traffic lights, runway lights, and lasers.
21
Q
How does a camera use light energy?
A
‘Captures’ images on film to make photographs.
22
Q
How does a projector use light energy?
A
Shines images onto a screen, such as in movies.
23
Q
How do traffic lights use light energy?
A
Differently-coloured lights guide traffic on the roads.
24
Q
How do runway lights use light energy?
A
Help planes land or take off.
25
How does a laser use light energy?
It produces a strong beam of light that can cut through very hard materials — it is also used in surgery.
26
What is a common misconception about how cats and owls see in the dark?
Wrong concept: Animals such as cats and owls have big, sparkling eyes which give off light to detect and see objects in the dark.
27
What is the correct concept about how cats and owls see in the dark?
Right concept: Cats and owls can see well in the dark because they have special, shiny layers of cells at the back of their retinas which reflect light back to the retina's cells.
28
What is heat energy?
Heat energy is a form of energy that makes things warm or hot.
29
How does heat energy from the Sun affect living things?
Heat energy from the Sun keeps living things warm so that they can survive.
30
What is a source of heat energy?
The Sun.
31
What are some uses of heat energy produced by the Sun?
Warms the surface of Earth, dries clothes, dries food, boils water.
32
What are some electrical appliances that produce heat energy?
Electric kettle, electric stove, rice cooker, oven, toaster, electric iron.
33
What is a natural source of heat energy?
Wood.
34
What are some uses of burning fuels?
Cooks food, irons clothes, provides warmth, provides heat for cooking, provides heat in industries.
35
How can heat energy be produced besides burning fuels?
By moving or rubbing things together.
36
What is sound energy?
Sound is a form of energy that we can hear, produced by *_VIBRATING_* objects.
37
How does sound travel?
Sound travels outwards from the object producing it towards our ears and needs a medium to travel through.
38
What are some mediums through which sound can travel?
Air, water, and wood.
39
Can sound travel in outer space?
No, sound does not travel in outer space, which is a vacuum.
40
What is a vacuum?
A vacuum contains no matter and is completely empty.
41
What are some sources of sound energy?
Various sources, including speech, song, and noise
## Footnote
Loud noise can be produced by sirens, fire alarms, and musical instruments.
42
What are examples of loud noise used for communication?
Sirens of ambulance, fire engines, fire alarms in buildings
## Footnote
These sounds are used to warn people of emergencies.
43
True or False: Sound can travel through a vacuum.
False
## Footnote
Sound needs a medium such as a solid, liquid, or gas to travel.
44
What unique ability do bats and dolphins have regarding sound?
They can make sounds that the human ear cannot hear.
## Footnote
These sounds form echoes that help them detect solid objects in their path.
45
What is electrical energy?
A form of energy that can be carried along wires
## Footnote
Electrical energy is also known as electricity.
46
How is electricity usually generated?
In power stations
## Footnote
Electricity can also be generated from batteries and solar cells.
47
Why is electrical energy very useful?
Electrical energy can easily be changed into other forms of energy:
* Light
* Heat
* Sound
48
TRUE or FALSE:
Sources of energy like batteries and electric mains provide energy in an OPEN circuit
FALSE:
The energy is provided in a CLOSED circuit
## Footnote
In a closed circuit, the current transports energy from the battery to other circuit components.
49
What is kinetic energy?
Kinetic energy is the energy that moving objects have.
50
TRUE OR FALSE:
Kinetic energy can only be found in non-living things.
FALSE:
Kinetic energy can be found in both living things and non-living things.
51
How does speed affect kinetic energy?
The faster an object moves, the more kinetic energy it has.
52
TRUE or FALSE:
Fluid objects like wind, and water, do NOT have kinetic energy.
False.
Kinetic energy is found in any moving objects, including wind and water
53
What are some effects or uses of wind kinetic energy?
* fun activities (such as flying kites and hang-gliding)
* moving sailboats
* turning wind turbines to generate electricity
* turning windmills to help farmers draw water or crush flour.
54
What are some effects, or uses of moving water kinetic energy?
* Moving water kinetic energy is used for fun activities (such as surfing)
* Generates electricity by turning turbines.
55
What factors affect the amount of kinetic energy an object has?
The amount of kinetic energy an object has depends on its *_MASS_* and *_SPEED_*.
56
How does mass affect kinetic energy?
Objects with *_MORE MASS_* have *_MORE KINETIC ENERGY_*.
For example, if a larger/heavier bus and a smaller/lighter car are moving at the same speed, the bus has more kinetic energy.
57
How does speed affect kinetic energy?
The *_FASTER_* an object moves, the *_MORE_* kinetic energy it has.
For example, if two *identical* buses are moving at *different* speeds, the bus that is moving FASTER has MORE kinetic energy.
58
TRUE OR FALSE:
Objects at rest do not have kinetic energy.
TRUE
Only moving objects have kinetic energy.
59
TRUE OR FALSE:
Objects at rest do not have kinetic energy.
TRUE
Only moving objects have kinetic energy.
60
What is kinetic energy?
Kinetic energy is the energy an object possesses due to its motion.
61
What is the relationship between mass and kinetic energy?
Kinetic energy depends on both the speed and the mass of the object.
62
What is potential energy?
Potential energy is also known as stored energy that can be transformed into other forms of energy.
63
List the different forms of potential energy.
* Chemical potential energy
* Elastic potential energy
* Gravitational potential energy
64
What is chemical potential energy?
Chemical potential energy is stored in food, fuel, or batteries.
65
Give examples of chemical potential energy sources.
* Food (vegetables, meat)
* Batteries (dry cells, mobile phone batteries)
* Fuels (wood, oil, charcoal, coal, natural gas, petrol)
66
How is stored energy in food released?
The stored energy in food is released by respiration.
67
How is stored energy in fuels released?
The stored energy in fuels is released by burning.
68
How is stored energy in batteries used?
The stored energy in batteries is used when they are in a closed electric circuit.
69
True or False: An object at rest has kinetic energy.
False
70
What is gravitational potential energy?
Any object that is above the ground, hanging from something, or on top of a slope has gravitational potential energy.
## Footnote
Examples include a plane taking off, a fruit hanging from a branch, and a toy car on a ramp.
71
What factors determine the amount of gravitational potential energy an object has?
The amount of gravitational potential energy depends on:
* its mass
* its height from the ground
72
How does mass affect gravitational potential energy?
Objects with more mass have more gravitational potential energy.
73
True or False: If two balls are at the same height, the ball with less mass will have more gravitational potential energy.
False
74
What happens to gravitational potential energy as height increases?
The higher an object is from the ground, the more gravitational potential energy it has.
75
Fill in the blank: If two identical balls are at different heights, the ball that is ______ will have more gravitational potential energy.
higher up
76
Two different balls, Ball A and Ball B, are at the same height.
If Ball A has mass of 20g, and Ball B has mass of 50g, which will have more gravitational potential energy?
Ball B (more mass) has more gravitational potential energy than Ball A (less mass).
77
Two identical balls hang above the ground.
If Ball X is _80 cm_ above the ground and Ball Y is _40 cm_ above the ground, which ball has MORE gravitational potential energy?
Ball X
78
If an apple hangs from a tree has gravitational potential energy, what happens when it falls?
When the apple falls, its gravitational potential energy converts into kinetic energy.
79
What is elastic potential energy?
Elastic potential energy is the energy an object has when it is stretched or compressed.
80
What happens to elastic potential energy when released?
Once released, the elastic potential energy converts into kinetic energy and the object returns to its original shape.
81
How does the amount of elastic potential energy change?
The more the object is stretched or compressed, the more elastic potential energy is stored.
82
What are examples of objects with elastic potential energy?
Examples of objects that have elastic potential energy include compressed springs and stretched rubber bands.
83
How is energy converted during photosynthesis?
Light energy from the Sun changes into chemical potential energy stored as food in the plant.
84
How is energy converted when a battery is used in a circuit?
Chemical potential energy stored in the battery changes into electrical energy carried by current in the circuit, which then changes into light energy given off by the bulb and heat energy given off by the bulb.
85
How is energy converted during respiration?
Chemical potential energy from food changes into heat energy, kinetic energy when we move, and other usable energy used in other life processes.
86
What happens to gravitational potential energy when a ball falls?
Gravitational potential energy changes into kinetic energy.
87
What type of energy do cyclists derive from food?
Kinetic energy
## Footnote
The cyclist eats food which is chemical potential energy that is converted to kinetic energy for movement.
88
What process do plants use to convert light energy into chemical potential energy?
Photosynthesis
## Footnote
Plants utilize light energy from the Sun to create food through photosynthesis.
89
What type of energy conversion occurs when a vehicle engine burns petrol?
Chemical potential energy to Kinetic energy
## Footnote
The engine uses chemical potential energy from fossil fuel to produce kinetic energy for movement.
90
What type of energy does an oven produce when it uses electrical energy?
Heat and light energy
## Footnote
An oven converts electrical energy into heat and light energy.
91
What energy change occurs when switching on a television?
Electrical energy → Sound energy + Light energy + Heat energy
## Footnote
The energy transformation involves electrical energy from the mains supply.
92
What energy transformation occurs when turning on a fan?
Electrical energy → Kinetic energy
## Footnote
The fan converts electrical energy from the mains supply into kinetic energy of the fan blades and air.
93
What is the energy change when lights are turned on?
Electrical energy → Light energy + Heat energy
## Footnote
The light bulbs convert electrical energy from the mains supply into light and heat energy.
94
What happens to electrical energy when an electric kettle is used?
Electrical energy → Heat energy + Light energy
## Footnote
The kettle converts electrical energy into heat energy for heating water and light energy from the filament.
95
What type of energy is generated in a hydroelectric power station?
Electrical energy
## Footnote
Electrical energy is generated through the conversion of various energy types in the hydroelectric process.
96
In a hydroelectric power station, what does stored water possess?
Gravitational potential energy
## Footnote
Stored water's gravitational potential energy is utilized to generate electricity.
97
What does kinetic energy of water change into in a hydroelectric power station?
Kinetic energy of the turbine
## Footnote
The moving water drives the turbine, converting its kinetic energy into that of the turbine.
98
What energy transformation occurs in a fuel-burning power station?
Chemical potential energy changes into heat energy
## Footnote
Fuels release heat energy when burned, which is essential for generating steam.
99
What type of energy do fuels have in a fuel-burning power station?
Chemical potential energy
## Footnote
This energy is released as heat when the fuels are burned.
100
What does heat energy of water change into in a fuel-burning power station?
Kinetic energy of steam
## Footnote
Heat energy is used to produce steam, which has kinetic energy that drives the turbine.
101
What type of energy does the turbine gain from steam in a fuel-burning power station?
Kinetic energy
## Footnote
The kinetic energy of steam is crucial for the turbine's operation.
102
In a hydroelectric power station, what energy does the generator produce?
Electrical energy
## Footnote
The generator converts the kinetic energy of the turbine into electrical energy.
103
True or False: A hydroelectric power station converts gravitational potential energy into electrical energy.
True
## Footnote
The conversion of energy types is a key process in hydroelectric power generation.
104
Fill in the blank: In a hydroelectric power station, kinetic energy of water changes into _______.
Kinetic energy of the turbine
## Footnote
This transformation is essential for energy generation.
105
Fill in the blank: In a fuel-burning power station, chemical potential energy of fuels is converted into _______.
Heat energy
## Footnote
This heat energy is then used to produce steam.
106
What is energy efficiency?
Energy efficiency is the amount of useful energy we get from a system.
## Footnote
Energy efficiency measures how effectively a system converts energy from one form to another.
107
True or False: Most energy transformations are very efficient.
False
## Footnote
Most energy transformations involve a loss of usable energy.
108
What serves as fuel for the human body?
Food
## Footnote
Food provides the energy necessary for various bodily activities.
109
What percentage of efficiency does the human body typically achieve in converting food into useful work?
Less than five percent
## Footnote
This means that a significant amount of energy from food is lost as heat.
110
What happens to the energy that is not converted into useful work in the human body?
It is lost as heat.
## Footnote
This heat loss is particularly noticeable during exercise.
111
Fill in the blank:
Most energy transformations are not very efficient as converting one form of energy to another always involve a loss of _______.
*_USABLE_* energy
## Footnote
This is a fundamental principle of energy conversion.
112
TRUE OR FALSE:
The Human body is like a machine; it requires fuel to operate.
TRUE:
The human body is like a machine that requires fuel (food) to function.
## Footnote
Both systems convert energy to perform work, but neither is perfectly efficient.
113
TRUE OR FALSE:
Energy conversions are frequently efficient, and do not often result in a loss of usable energy.
False.
