Energy and Energy Resources

Question 1

Useful energy is…

Answer 1

.. energy in the form and place we want it

Question 2

What happens when energy dissipates?

Answer 2

It becomes less and less useful

It heats up the surroundinds

Question 3

How does the gravitational potential energy of an object change?

Answer 3

• when it goes UP, it INCREASES

- when it goes DOWN, it DECREASES

Question 4

What are the best conductors of energy and why?

Answer 4

Metals

- they have free electrons that move up and down the material

Question 5

What is an Elastic Potential Energy store?

Answer 5

The energy stored in a springy object when it is stretched or squashed

Question 6

Disadvantages of Nuclear Power

Answer 6

• used fuel rods contain radioactive waste
• an explosion would disperse radioactive waste over a wide area
• stations are expensive to build, run and decommission

Question 7

Work done is …

Answer 7

.. when an object moves as a result of a force

Question 8

How is energy transferred?

Answer 8

Via

• heating
• waves
• an electrical current
• a force

Question 9

ENERGY CANNOT BE CREATED…

Answer 9

…OR DESTROYED

Question 10

A closed system is …

Answer 10

.. an isolated system where no energy transfers into or out of the systems energy store

Question 11

What is a gravitational potential energy store?

Answer 11

The energy stored in an object because of its position

- eg. Above the ground

Question 13

What effects kinetic energy in a moving object?

Answer 13

Its mass and speed

Question 14

Wasted energy is …

Answer 14

.. energy that is NOT useful

- not in the form and place we want it

Question 15

What is Wave Power?

Answer 15

Energy generated by waves when they turn turbines

Question 16

What is a Thermal Energy store?

Answer 16

The energy a substance has due to its temperature

Question 17

How can machines be made more efficient?

Answer 17

By reducing the energy they waste

- eg. lubrication to reduce friction

Question 18

Why do machines waste energy?

Answer 18

Because of friction, air resistance, electrical resistance and noise

Question 19

What happens to the energy store when an object falls?

Answer 19

• gravitational potential energy DECREASES

- kinetic energy INCREASES

Question 20

What is a bio-fuel?

Answer 20

Any fuel taken from living or recently living organisms
Eg. Animal waste, ethanol, straw, nutshells, woodchip
They are …
-renewable and carbon-neutral

Question 22

Where does the wasted energy go?

Answer 22

It is transferred to the surroundings which become warmer

Question 23

Everyday electrical appliances include …

Answer 23

Heating
Lighting
Making objects move
Producing sound and visual images

Question 24

The thicker the layer of insulation,

Answer 24

the lower the rate of energy transfer through it.

Question 25

What are Kinetic Energy stores?

Answer 25

The enegy an object has bacause it is moving

Question 26

Electrical appliances can …

Answer 26

.. transfer useful energy at the flick of a switch

Question 26

Infrared radiation is emitted and absorbed by ...

Answer 26

.. all objects

Question 27

The higher the thermal conductivity of a material,

Answer 27

the higher the rate of energy transfer through it

Question 28

What are chemical energy stores?

Answer 28

The energy transfered during chemical reactions - fuels - foods

Question 29

The greater the mass of an object ...

Answer 29

.. the slower its temperature increases when it's heated

Question 30

The hotter an object is...

Answer 30

.. the more infrared radiation it emits in a given time

Question 32

How can the rate of energy transfer from houses be reduced?

Answer 32

- loft insulation - cavity wall insultation - double-glazed windows - aluminium foil behind radiators - external walls with thicker bricks and lower thermal conductivity

Question 33

What are the best insulators?

Answer 33

Wool and fibreglass

Question 33

The temperature of an object increases if ...

Answer 33

.. it absorbs more radiation than it emits

Question 35

The specific heat capacity of a substance is ...

Answer 35

.. the amount of energy needed to change the temperature of 1kg of the substance by 1*

Question 36

What happens to the energy store when an object falls, hits and stays on the ground?

Answer 36

- the kinetic energy DECREASES - most or all of the energy is transferred to its surroundings - the thermal energy of the surroundings INCREASES - energy can be lost through sound

Question 36

What is Nuclear power?

Answer 36

Nuclear fuel takes energy from atoms The nucleus of Uranium is unstable and can split in two. When this happens energy is transferred from the nucleus. All the atoms together become very hot.

Question 37

What is Wind Power?

Answer 37

Energy generated from wind turbines

Question 37

What is Hydroelectric Power?

Answer 37

Energy generated when rainwater that's collected in reservoirs flows downhill through turbines

Question 38

What does a Tidal Power station do?

Answer 38

It traps water from high tide, which can then be released through turbines. This generates electricity.

Question 40

Fossil fuels produce increased levels of ...

Answer 40

.. greenhouse gases, which contribute to global warming

Question 41

Most of our energy comes from ...

Answer 41

.. burning fossil fuels

Question 41

What is Solar Power?

Answer 41

Energy from the sun that is absorbed by solar cells that can be used to directly generate electricity.

Question 42

Disadvantages of Renewable energy sources

Answer 42

- not yet able to meet the world demand - unreliable - expensive to install - WIND = loud and unsightly - TIDAL = effect river habitats - HYDROELECTRIC = habitats flooded to create reservoirs - SOLAR = need to cover a large area for lots of energy

Question 43

What is Geothermal Energy?

Answer 43

Energy released by radioactive substances deep beneath the earth. The radioactive substances heat surrounding rocks. Stations pump water on them to produce steam which drives the turbines.

Question 44

Advantages of Nuclear Power

Answer 44

- no greenhouse gases | - more energy transferred per kg of uranium than fossil fuels

Question 45

Advantages of Renewable energy sources

Answer 45

- never run out - don't produce greenhouse gases - don't produce radioactive waste - cheap to run

Question 46

What is convection and wher does it occur?

Answer 46

- gases and liquid | - when a change in density causes particals to move from HOTTER to COLDER regions

Question 47

Advantages of fossil fuels

Answer 47

- accessible - provide a large amount of concentrated energy - relatively low cost

Question 48

Disadvantages of fossil fuels

Answer 48

- non-renewable - produce co2 when burned - release sulfer when burned