Topic 1 3rd Form

Question 1

6 energy stores (we’ve learnt)

Answer 1

Thermal, kinetic energy, GPE, chemical energy, magnetic and nuclear

Question 2

4Ways energy can be transferred

Answer 2

Mechanically
Electrically
By heating
By radiation

Question 3

A falling apple

Answer 3

Gravitational potential to kinetic energy

Question 4

A battery powering torch

Answer 4

Chemical to electrical to light and thermal

Question 5

Rubbing your hands

Answer 5

Kinetic to thermal (by friction)

Question 6

A toaster

Answer 6

Electrical to thermal

Question 7

What is kinetic energy

Answer 7

Kinetic energy is the energy an object has because it is moving

Question 8

Formula for kinetic energy

Answer 8

KE = 1/2 x m x v^2

Question 9

Energy TRANSFERS between kinetic and gravitational potential energy

Answer 9

When an object rises, kinetics energy is converted into gravitational potential energy
When it falls, gravitational potential energy converts into kinetic energy

Question 10

Formula gravitational potential energy

Answer 10

GPE = m x g x h

Question 11

g

Answer 11

9.8 N/kg OR 10 N/kg

Question 12

Gravity

Answer 12

Gravity is the force that pulls masses toward each other, like towards Earth

Question 13

Weight

Answer 13

Weight is the force of gravity on an object

Question 14

Formula for weight

Answer 14

Mass x gravitational field strength

Question 15

Gravitational potential energy (GPE)

Answer 15

gravitational potential energy is energy an object has because of its height above the ground

Question 16

Formula GPE

Answer 16

m x g x h

Question 17

What does “conservation of energy” mean?

Answer 17

The total energy in a close system stays the same. Energy can change form but it is not created or destroyed.

Question 18

Power

Answer 18

Power measures how quickly energy is transferred or work is done

Question 19

Formula power (2)

Answer 19

Energy transferred divided by time OR work done divided by time

Question 20

Friction turns useful … energy into wasted … energy

Answer 20

Kinetic energy, thermal energy

Question 21

What carries energy away?

Answer 21

Sound and vibrations

Question 22

What is lossed to the environment?

Answer 22

Heat

Question 23

Insulate

Answer 23

Stop heat leaving

Question 24

Lubricant

Answer 24

Use ball bearings to reduce friction

Question 25

Streamline shapes

Answer 25

To reduce air resistance

Question 26

Seal gaps and draughts

Answer 26

reduce unwanted heat transfer

Question 27

4 ways to reduce friction

Answer 27

Use lubricants Fit ball bearings or rollers Make surfaces smoother Use wheels instead of dragging things

Question 28

Efficiency

Answer 28

Efficiency is the bit of input energy that is usefully transferred to the output you want

Question 29

Formula efficiency

Answer 29

Useful output energy divided by total input energy

Question 30

What must you do if it’s % efficiency

Answer 30

Multiply result for efficiency by 100

Question 31

Is there any device that is 100% efficient

Answer 31

No, as some energy is always wasted so real devices are less than 100% efficient 

Question 32

Main energy resources we rely on 4

Answer 32

Renewable: solar, wind Non-renewable : coal, oil

Question 33

What is the difference between renewable and non-renewable resources?

Answer 33

Renewable resources are naturally replenished and won’t run out on human timescales non-renewable resources take millions of years to form and can be used up.

Question 34

How does solar power work?

Answer 34

Generate electric currents directly from sunlight

Question 35

What are 2 pros and cons of solar power

Answer 35

Pros: no fuel cost, can be on roofs Cons: relies on the sun, initial cost is high

Question 36

How does wind power work?

Answer 36

Wind turns turbine blades, which spin a generator to make electricity. The moving airs kinetic energy becomes electrical energy

Question 37

Pros and cons of wind power

Answer 37

Pros: no fuel cost, turbines can be on land + sea Cons: can be noisy, can affect wildlife (birds)

Question 38

How does geothermal energy work?

Answer 38

Geothermal energy uses heat from inside the Earth to generate electricity or heat buildings directly

Question 39

What are the pros and cons of geothermal power?

Answer 39

Pros: reliable, works day and night Cons: location dependent, can cause local environmental issues

Question 40

How do hydroelectric dams and tidal bars transfer gravitational potential energy to kinetic energy?

Answer 40

Water held at height (high GPE) , flows down or through gates and gain speed (kinetic) which turns turbine blades.

Question 41

Pros and cons of hydro/tidal power?

Answer 41

Pros: reliable, long lifetime Cons : changes habitats, expensive to build

Question 42

What are fossil fuels?

Answer 42

Fossil fuels are fuels formed from ancient plants and animals and take millions of years to form

Question 43

What are the pros and cons of fossil fuels?

Answer 43

Pros: existing infrastructure, high energy density Cons: non-renewable, contributes to climate change

Question 44

What is nuclear energy?

Answer 44

Nuclear energy comes from splitting atoms of uranium to release heat that makes electricity

Question 45

What are the pros and cons of nuclear energy?

Answer 45

Pros: reliable base load power, very low greenhouse gas emissions Cons: radioactive waste that must be sorted safely, fuel is non-renewable

Question 46

How do hydroelectric dams work?

Answer 46

Water stored at height has gravitational potential energy when released it flows down converting GPE to kinetic energy that turns turbines to make electricity

Question 47

How do tidal barrages work?

Answer 47

Incoming and outgoing tides move water through turbines the moving water energy turns generators.

Question 48

1 joule per second is equal to the power of.. watts

Answer 48

1 watt

Question 49

1 joule is

Answer 49

1 newton-metre