Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gcse Physics > Energy > Flashcards

Energy Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards GCSE Religious Studies - Edexcel Route A flashcards AP® Physics flashcards GCSE Religious Studies - Eduqas Route A flashcards GCSE Geography - AQA flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

What is the equation for kinetic energy? Give SI units for all quantities involved.

A

1/2 m v2
1/2 x mass x (velocity)2
Energy (J), Mass(kg), Velocity(m/s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the equation for elastic potential energy? Give SI units for all quantities involved.

A

1/2 k x2
1/2 x Spring Constant x (Extension)2
Energy (J), Spring Constant (N/m), Extension(m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the equation for gravity potential energy? Give SI units for all quantities involved.

A

mgh
Mass x Gravitational Field strength x Height
Energy (J), Mass(kg), Gravitational Field strength (N/kg), Height(m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define the “Specific Heat Capacity “ of a substance.

A

The amount of energy needed to raise the substance the temperature of 1 kilogram of a substance by 1 degree Celsius.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

State the units for Specific Heat Capacity

A

J/*C/kg
Joules/Degree Celsius/Kilogram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the definition of “Power”?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

State two equations for power. Give SI units for all quantities involved.

A

power= energy transferred/time power = work done/time
Energy (J), Work Done (J), Time (s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the unit of power?

A

Watt (W)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Two motors lift the same mass through the same height. Motor A. The energy transferred is the same but the time taken is less (P=E/t).

A

Motor A.
The energy transferred is the same but the time taken is less (P=E/t).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the energy changes involved when a ball is thrown upwards and then returns to its starting position. Ignore air resistance.

A
  • Upwards: KE is converted to GPE
  • Peak: Maximum GPE, zero KE
  • Downwards: GPE is converted to KE

KE (is converted to GPE), GPE (Gravitational Potential Energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the energy transfers for a bungee jumper.

A
  • When falling, the GPE is converted to KE of jumper
  • As the cord tightens, KE is converted and stored as Elastic Potential Energy (EPE)
  • At lowest point, the jumper’s initial GPE equals the EPE stored in the cord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain why a bungee jumper slows down once the
cord begins to stretch.

A

· Kinetic energy decreases since it is
converted to elastic potential energy
. Since KE is proportional to (velocity)2,
as KE decreases, so does velocity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Give examples of chemical energy stores.

A

· Food
· Fuel (eg. wood, coal, petrol)
· Batteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

State 4 different stores of energy.

A
  1. Kinetic Energy
  2. Gravitational Potential Energy
  3. Elastic Potential Energy
  4. Chemical Energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

State the law of energy conservation.

A

Energy cannot be created or destroyed
(it can only be transferred into different
forms).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

State any changes in the total energy of a ball that
is kicked, assuming that no external forces act.

A

The total energy of the system remains
constant due to the conservation of
energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is waste energy?

A

The energy that is not used by the device
for its desired purpose.

18
Q

Describe the energy changes that occur
in a filament light-bulb.

A

Electrical energy is transferred into
light and heat energy
Light is a useful energy form, heat is
waste energy

19
Q

State two equations to calculate efficiency.

A

=Useful Output Energy Transfer/Total
Input Energy Transfer

=Useful Power Output/Total Power
Output

20
Q

How can the efficiency of a system be increased?

A
  1. Reducing waste output (by
    lubrication, thermal insulation etc.)
  2. Recycling waste output (eg. recycling
    thermal waste energy as input energy)
21
Q

State the consequence for energy transfer of a
material with a igh thermal conductivity.

A

The rate of energy transfer through the
material is higher than for a material with
a lower thermal conductivity.

22
Q

Do double-glazed windows have a higher or lower
thermal conductivity than single-glazed windows?

A

Lower, meaning less energy transfers
through them.

23
Q

What key factors affect the rate of cooling of a
building?

A

. The thickness of the walls
. The thermal conductivity of the walls

24
Q

State three methods of reducing heat
loss in a building.

A
  1. Double glazing
  2. Loft and wall insulation
  3. Thicker walls
25
Q

How can the efficiency of a mechanical machine with
moving parts be improved?

A

Lubricate any moving parts to reduce the
friction and therefore energy loss due to
heating.

26
Q

How can the efficiency of a radiator be improved?

A

Installing metal foil sheets behind the
radiator to reflect the heat back into the
room rather than it being absorbed into
the walls.

27
Q

How can the efficiency of boiling water in a pan be
improved?

A

By placing a lid on the pan to reduce the
heat loss from the top.

28
Q

What is a renewable energy resource?

A

An energy source which can be
replenished as it is being used up.

29
Q

Give four examples of renewable energy resources.

A
  1. Wind Energy
  2. Hydro-Electricity
  3. Tidal Energy
  4. Solar Energy
30
Q

Give an example of a non-renewable energy
resource.

A

Fossil fuels (for example coal, oil and
gas).

31
Q

What are the advantages of generating power using
gas rather than coal?

A

· Flexible Generation: Gas power
stations have short start-up times so
can be switched on/off more readily
. Lower emissions of carbon dioxide

32
Q

State two disadvantages of using renewable energy
resources to generate power.

A

· Output often determined by external factors
(like wind speed), so supply is uncertain
· Generating power through other means is
often more efficient and economically
beneficial

33
Q

Explain the environmental impacts of
burning fossil fuels.

A

. Carbon Dioxide contributes to the
greenhouse effect, and causes global
warming
. Sulphur Dioxide leads to acid rain, which
can damage buildings and crops

34
Q

State three advantages of fossil fuels as an energy
resource.

A
  1. Reliable: Not dependent on external factors
    so can generate power anytime
  2. Can produce large amounts of energy for a
    given quantity
  3. Still relatively abundant, so cost-effective
35
Q

State three advantages of nuclear
power.

A
  1. Very large amounts of energy for relatively
    small quantities of fuel
  2. Doesn’t release greenhouse gases and so
    doesn’t contribute to climate change
  3. Low fuel costs
36
Q

State three disadvantages of nuclear power.

A
  1. Produces nuclear waste which is harmful to
    humans & must be safely stored for centuries.
  2. Non-Renewable energy source
  3. Risk of nuclear accidents, which have fatal
    consequences on humans and the
    environment
37
Q

How does hydroelectric power produce energy?

A

. Rainwater collects behind a dam
· When this water is released, it is used
to turn a turbine
. This turbine turns a generator which
produces electricity

38
Q

What are some disadvantages of using biofuels?

A

. When plants are burned or decay they release CO2
. In order to grow biofuels, you need to destroy land
which leads to problems because:
The land could have been natural habitats
Destroying land may involve burning plants growing
on it, which would release CO2
- Growing biofuels reduces the land available for growing
food

39
Q

What are the advantages of tidal energy sources?

A

· They do not produce greenhouse gases
· They are quite reliable, as tides happen
twice a day
. They are cheap to run as tides are
natural, and so are free

40
Q

What are the disadvantages of hydroelectric power?

A

. The dam may cause flooding
. It can cost a lot to install the required
infrastructure

41
Q

What are some advantages of solar panels?

A

. They don’t cause harm to the
environment
. They are a renewable resource
. They can be used in remote areas where
other types of energy are less accessible

42
Q

Give an example of a social factor which may act as
a deterrent for certain types of energy production.

A

· Visual Pollution
. Sound Pollution

(both of these are disadvantages of wind farms)

Gcse Physics (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions