Energy and Energy Resources

Question 1

What is specific heat capacity

Answer 1

Amount of energy required to raise temperature of 1kg of a material by 1 degree

Question 2

Specific heat capacity is the amount of energy needed to raise the temperature of…

Answer 2

1kg of a material by 1 degree

Question 3

When a substance is heated/ cooled the temperature change depends on

Answer 3

Substance’s mass
Type of material
How much energy is transferred to it

Question 4

What does the thermal conductivity of a material tell us

Answer 4

How quickly energy is transmitted through it by thermal conduction

Question 5

If something has a high thermal conductivity will heat be lost quickly or slowly

Answer 5

Quickly
High thermal conductivity = higher rate of heat loss

Question 6

If something has a low thermal conductivity will heat be lost quickly or slowly

Answer 6

Slowly
Low thermal conductivity = lower rate of heat loss

Question 7

Which has a higher rate of heat loss out of low and high thermal conductivity

Answer 7

High
High thermal conductivity = higher rate of heat loss and vice versa

Question 8

Thermal insulators have low

Answer 8

Thermal conductivity (lower rate of heat loss)

Question 9

3 things the energy transfer per second through a material depends on

Answer 9

Material’s thermal conductivity
Temperature difference between 2 sides of a material
Thickness of material

Question 10

True or false, all objects emit and absorb infrared radiation

Answer 10

True

Question 11

True or false, the higher the temperature if an object then the more infrared radiation that’s emitted (in a given time)

Answer 11

True

Question 12

What is meant by a ‘black body’

Answer 12

Theoretical object that absorbs 100% of radiation that falls on it

Question 13

What is internal energy

Answer 13

Total kinetic and potential energy of particles in substance

Question 14

Which 2 stores is internal energy compromised of

Answer 14

Potential and kinetic

Question 15

What is the specific heat capacity of water if it requires 4200J to raise the temperature of 1kg of it by 1 degree

Answer 15

4200J
(As specific heat capacity is ENERGY required to raise temperature of 1kg of material by 1 degree)

Question 16

Specific heat capacity is also the amount of energy released as a substance…

Answer 16

Cools
(E.g if water requires 4200J for the temperature of 1kg of it to be raised by 1 degree then if 1kg of it is cooled by 1 degree it will also give out 4200J)

Question 17

Specific heat capacity is also the

Answer 17

Amount of energy released when 1kg of a substance cools by 1 degree

Question 18

For specific heat capacity what is the unit for mass

Answer 18

Kg

Question 19

Complete this question:
Find the final temperature of 800g of water (with specific heat capacity of 4200J/ Kg degrees) at an initial temperature of 20 degrees after 20kJ of energy has been transferred to it

Answer 19

25.95 degrees

Equation given to you: Change in energy (J)= Mass (Kg) x Specific heat capacity (J/ Kg degrees) x change in temperature (degrees)

800g= 0.8kg
20kJ= 20,000J

20,000= 0.8 x 4200 x temp change
Temp change = 20,000/ (0.8 x 4200)
Temp change = 5.95 degrees (2dp)

20+ 5.95= 25.95 degrees

Question 20

Definition of temperature

Answer 20

Average kinetic energy of particles in the substance

Question 21

Why do particles in a solid have kinetic energy

Answer 21

They are vibrating

Question 22

Why do particles in a liquid/ gas have kinetic energy

Answer 22

They are moving around

Question 23

True or false a material with a higher specific heat capacity needs more energy to change its temperature

Answer 23

True

Question 24

What is the equation for specific heat capacity (it’s given to you in the exam)

Answer 24

Energy= mass x specific heat capacity x temperature change
Specific heat capacity = energy/ mass x temperature change

Question 25

How do we measure power (of the heater) for specific heat capacity rpa

Answer 25

Power=Current x potential difference P= IV (Penguins in Vegas) Power needs to be measure to be multiplied by time to get energy as power= energy transferred/ time We can use our energy value to put into the specific heat capacity equation to find specific heat capacity using our results

Question 26

List the 8 energy stores

Answer 26

Chemical Kinetic Vibrational Nuclear Elastic potential Gravitational potential Thermal Electrical

Question 27

Equation for kinetic energy

Answer 27

Kinetic energy = 0.5 x mass x speed^2

Question 28

Equation for work done (energy transferred)

Answer 28

Work done = force x distance moved

Question 29

Equation to find weight

Answer 29

Mass x gravitational field strength

Question 30

Equation to find (change in) gravitational potential energy

Answer 30

(Change in) height x mass x gravitational field strength

Question 31

Equation linking power, energy transferred and time

Answer 31

Power = energy transferred/ time

Question 32

2 ways we can insulate our homes

Answer 32

Double glaze windows- trap layer of air between glass (air is a good insulator so reduces/ slows down rate of heat loss) Cavity wall insulation- space between 2 layers of brick to trap air (again slows down heat transfer)

Question 33

What does renewable mean

Answer 33

Can be replenished Cannot be depleted (there isn't less of it after you've used it) Can't be reused Won't run out

Question 34

What type of source can be replenished

Answer 34

Renewable

Question 35

Reliability meaning

Answer 35

Can be depended upon Quality of being trustworthy/ performing consistently well

Question 36

Which energy resources are renewable

Answer 36

All except fossil fuels and nuclear Solar Wind Hydroelectric Tidal Wave Biofuel Geothermal

Question 37

Which 4 energy resources are reliable

Answer 37

Fossil fuels Hydroelectric Nuclear Geothermal

Question 38

True or false, fossil fuels are the only energy resource to produce CO2

Answer 38

True Biofuel also does but it's carbon neutral

Question 39

Which 3 energy resources are unreliable

Answer 39

Solar Wind Wave

Question 40

Which energy resource has the highest energy density (advantage)

Answer 40

Nuclear

Question 41

For specific heat capacity RPA why must the block be insulated

Answer 41

Stop heat being lost to atmosphere

Question 42

Specific heat capacity RPA method

Answer 42

1) Measure and record mass of block in KG 2) place heater in larger hole in block 3) connect ammeter, heater and power pack in series and voltmeter across power pack in parallel 4) with pipette add small amount of water to other hole and place thermometer inside 5) turn on power pack to 12V and record current and potential difference with voltmeter and ammeter 6) turn on stop clock and measure temperature every minute for 10 mins

Question 43

For specific heat capacity why might your specific heat capacity value not be the true value

Answer 43

Not all heat is transferred from heater into block and through thermometer

Question 44

Briefly outline thermal insulation practical

Answer 44

1) boil water with kettle 2) measure fixed volume of water with beaker then wrap with first material including a lid with a hole in 3) place there enter through hole and measure initial temperature 4) turn on stopwatch and measure temperature every 2 mins for 20 mins 5) repeat using different materials 6) plot graph comparing time to temperature.