# Energy Flashcards

1
Q

What is elastic energy?

A

Elastic potential energy is stored when an object is stretched or squashed eg. compressed springs, inflated balloons.

2
Q

What is kinetic energy?

A

Kinetic energy is the energy of a moving object. Eg. Runner, Buses.

3
Q

What is thermal energy?

A
• The total kinetic and potential energy of particles in an object.
• This is in the vibrations of the object - Kinetic energy.
• Increasing separation of molecules requires work to be done by the potential energy store.
• In hotter objects, they have more thermal energy and vibrate faster.
4
Q

What is chemical energy?

A
• Energy stored in chemical bonds.

- Can release energy by a chemical reaction. Eg. Food, Fuels, Batteries.

5
Q

What is nuclear energy?

A
• Energy stored in the nucleus of an atom.
6
Q

What is electrostatic energy?

A
• Energy sored when repelling charges move closer together or when attracting charges are pulled further apart.
7
Q

What is magnetic energy?

A
• Energy stored when repelling poles are pushed closer together and attracting poles move further apart. eg. a fridge magnet, maglev trains.
8
Q

What is mechanical work?

A
• Mechanical work is a force moving an object through a distance.
9
Q

What is electric work?

A
• Electric work is when charges are moving due to a potential difference.
10
Q

What is voltage?

A
• Voltage is the measure of energy given to charge carriers.
11
Q

What is potential difference?

A
• Potential difference is the voltage between two points that make an electric current flow.
12
Q

What is heating?

A
• Heating is an energy transfer due to temperature difference caused electrically or by a chemical reaction.
13
Q

A
• Radiation is energy transferred by waves. eg. light, infrared radiation emitted from the sun.
14
Q

What are energy flow diagrams?

A
• Energy flow diagrams show how energy is transferred from one store to another.
15
Q

What is work?

A
• Work is the measure of energy transfer when a force moves an object through a distance.
16
Q

What are work done and energy transferred measured in ?

A
• Work done and energy transferred are measured in Joules.
17
Q

What is power?

A
• Power is the rate energy is transferred per second.
18
Q

What is the equation for work done?

A
• Word done = force x distance
19
Q

What is the equation for power?

A
• power = work done/ time
20
Q

What is efficiency?

A

Efficiency: How good a device is at transferring energy input to useful energy output.

21
Q

What is the equation of efficiency?

A

Efficiency = useful energy transferred/ total energy supplied x 100 .

22
Q

How many milijoules are in a joule?

A
• A millijoule is 0.001J. so 1/1000 of a Joule.
23
Q

How many kilojoules are in a joule?

A
• 1000J in a kilojoule.
24
Q

What is “The Law of the Conservation of energy?”

A
• The Law of Conservation means that the total energy before transfer is the same as the total energy after transfer because it cannot be created/ destroyed.
25
Q

Who is the “Joule” named after?

A
• The Joule is named after James Prescott Joule (scientist.)
26
Q

Give two examples of energy transfer diagrams.

A
• Transfer diagram.

- Sankey diagram.

27
Q

What does it mean if energy is dissipated?

A
• Dissipation is the transfer of energy stores into less useful ones. Known as “wasted” energy.
28
Q

Why is a lubricant used?

A
• Lubricants are used to reduce the amount of friction, therefore decreasing the thermal energy.
• Energy will not be dissipated.
29
Q

Why are LED lights more efficient than filament lights?

A
• They are energy efficient, producing less heat (dissipated energy.)
30
Q

Give an example of energy dissipation.

A
• Electrical work in tumble dryers.
• Transferred to useful thermal energy.
• Dissipated into sound waves
31
Q

What is the calculation for the amount of kinetic energy?

A

Kinetic energy = 1/2x mass x speed (squared)

32
Q

When using the formula for kinetic energy, what is the measure of mass?

A
• The measure of the mass is Kg.
33
Q

How much kinetic energy does a 30 kg dog have when it runs at 4 m/s?

A
• 240J
34
Q

What is the formula for the calculation of kinetic energy?

A

Ek = 1/2mv(squared.)

35
Q

What is a renewable energy source?

A
• A renewable energy source is one that is being (or can be) replenished as it is used.
36
Q

Give two advantages of renewable energy resources.

A
• Renewable energy will never run out.

- Once in place, will not add CO2 to atmosphere, not contributing to climate change.

37
Q

Hydroelectric power is very reliable, so what is the issue with it?

A
• Many habitats are destroyed when building them.

- Only suitable in countries with a lot of rivers, not the UK.

38
Q

What is geothermal energy?

A
• Geothermal energy is using the heat from the earth to generate electricity.
39
Q

What is a fossil fuel?

A
• A fossil fuel is a finite resource that releases energy.
40
Q

What is the difference between temperature and thermal energy?

A
• Temperature is how cold/ hot something is. Depends on how fast particles are moving.
• Thermal energy - The more particles (larger it is) more the thermal energy.
41
Q

What is heat?

A
• Heat is the transfer of thermal energy from a warmer object to a colder object.
42
Q

What is thermal energy affected by and why?

A
• Mass and size.
• Total amount of kinetic + potential energy.
• The bigger it is , the more thermal energy it has because it has more particles.