Energy

Question 1

What is kinetic energy?

Answer 1

the energy stored in moving objects.

Question 2

calculate kinetic energy for a moving object…

Answer 2

kinetic energy = 0.5 x mass x speed (squared)
Ek = 0.5 x m x V2

Question 3

What is the unit for kinetic energy?

Answer 3

J

Question 4

What is the unit for mass?

Answer 4

Kg

Question 5

What is the unit for speed?

Answer 5

m/s

Question 6

What is the store of a force placed on a stretched spring?

Answer 6

elastic potential energy

Question 7

What is the equation of elastic potential energy?

Answer 7

elastic potential energy = 0.5 x spring constant x extension

Ek = 0.5 x k x e2

Question 8

What is the unit for elastic potential energy?

Answer 8

J

Question 9

What is the unit for the spring constant?

Answer 9

N/m

Question 10

What is the unit for extension?

Answer 10

m

Question 11

What is the equation for gravitational potential energy?

Answer 11

gravitational potential energy = mass × gravitational field strength × height

Question 12

what is the unit for gravitational potential energy?

Answer 12

J

Question 13

what is the unit for mass?

Answer 13

Kg

Question 14

What is the unit for gravitational field strength?

Answer 14

N/Kg

Question 15

What is the unit for height?

Answer 15

m

Question 16

what is specific heat capacity?

Answer 16

how much heat energy is needed to raise the temperature of a substance by one degree Celsius per unit mass.

Question 17

What is the equation for specific heat capacity?

Answer 17

change in thermal energy = mass × specific heat capacity × temperature change

Question 18

What is unit of change in thermal energy?

Answer 18

J

Question 19

What is the unit for mass?

Answer 19

Kg

Question 20

What is the unit for specific heat capacity?

Answer 20

J/Kg

Question 21

What is the unit for temperature?

Answer 21

C

Question 22

What is gravitational potential energy?

Answer 22

the energy stored due to an object’s position above the ground.

Question 23

What is thermal energy?

Answer 23

the energy stored due to an object’s temp.

Question 24

What is the law of conservation of energy?

Answer 24

energy can be transferred, stored or dissipated but cannot be created or destroyed.

Question 25

How can we reduce unwanted energy transfers?

Answer 25

reduce the amount of friction

Question 26

What is work done?

Answer 26

when energy is transferred from one store to another.

Question 27

What does mechanical work require?

Answer 27

a force to move an object

Question 28

What does electrical work require?

Answer 28

a current transfering energy.

Question 29

what is the equation for work done?

Answer 29

work done = force x distance

Question 30

what is the unit for work done?

Answer 30

J

Question 31

what is the unit for force?

Answer 31

N

Question 32

What is the unit for distance?

Answer 32

m

Question 33

What is power?

Answer 33

power is the rate at which energy is transferred or the rate at which work is done.

Question 34

What is the first equation for power?

Answer 34

power = energy transferred / time

Question 35

What is the second equation for power?

Answer 35

power = work done / time

Question 36

What is the unit for power?

Answer 36

W

Question 37

what is the unit for work done/ energy transferred?

Answer 37

J

Question 38

What is the unit for time?

Answer 38

S

Question 39

What is the equation for efficiency?

Answer 39

efficiency = useful output energy transfer / total input energy transfer efficiency = useful power output / total power output

Question 40

How are modern houses built?

Answer 40

external brick and internal breezeblock between them is a cavity with insulating material which has very low thermal conductivity.

Question 41

How are windows built?

Answer 41

double glazed --> low thermal conductivity

Question 42

What does the loft contain?

Answer 42

insulation --> low thermal conductivity

Question 43

What are the three main fossil fuels?

Answer 43

coal/oil/gas

Question 44

What are the advantages of fossil fuels?

Answer 44

reliable release a great deal of energy abundant cheap

Question 45

What are the disadvantages of using fossil fuels?

Answer 45

release a huge amount of carbon dioxide non-renewable release other pollutants

Question 46

Is nuclear power non-renewable or renewable?

Answer 46

non-renewable

Question 47

What are the advantages of using nuclear power?

Answer 47

does not release CO2 --> does not contribute to climate change extremely reliable

Question 48

What are the disadvantages of using nuclear power?

Answer 48

contains highly dangerous radioactive material decommissioning a nuclear power is extremely expensive radioactive waste must be stored for thousands of years before being safe.

Question 49

What are the benefits from switching from coal to gas?

Answer 49

generates less CO2 --> contributes less to climate change. gas-fired power stations --> switched on quickly during periods of high demand

Question 50

What is a renewable energy source?

Answer 50

a energy source that is being replenished as it is used.

Question 51

name the 7 renewable energy sources:

Answer 51

1) wind power 2) solar power 3) hydroelectric power 4) tidal power 5) biofuels 6) wave power 7) geothermal

Question 52

What are the benefits of renewable energy sources?

Answer 52

will never run out once in place do not add any CO2

Question 53

what are the disadvantages of wind and solar power?

Answer 53

can be unreliable

Question 54

What are benefit and disadvantages of hydroelectric power?

Answer 54

reliable but habitats destroyed

Question 55

What are benefit and disadvantages of hydroelectric power?

Answer 55

reliable harmful to wildlife

Question 56

What are benefit and disadvantages of wave power?

Answer 56

small scale extremely reliable