Topic 2 - energy THERMAL PHYSICS

Question 1

What is chemical energy strore ?

Answer 1

Incldues fuels , foods or chemicals found in bateries .

Question 2

What is kinetic energys troes ?

Answer 2

includes energy of object because it is movign .

Question 3

What is gravtiational potenitaly energy?

Answer 3

Describes energys tores of an object because of its position , such as an object above the ground .

Question 4

What is elastic potential nergy ?

Answer 4

energy store in an object when it is streched or swaushed

Question 5

What is elastic potential energy ?

Answer 5

Used to desrvive energy in a springy object when you strech or squash it .

Question 6

What is thermal energys tore ?

Answer 6

Describes energy of a substance due to its temp ..

Question 7

enertransfers in a torch lamp .

Answer 7

Chemcial energys tores in batter —> electric current in wired –> energy transgferrred to surroudnigns as light waves + thermal energys tore of surroudnigns ..
object falling
gpe —> kinetic energy store –> energ of surroundings —> thermal energys tore of surroudnigns and sound waves .

Question 8

Four ways energy can be transferred .,

Answer 8

Mechanically - By the action of a force.
Electrically - By an electrical current.
By radiation - By Light waves or Sound waves.
By heating - By conduction, convection or radiation.

Question 9

What is the law of conservation of energy ?

Answer 9

Enrgy can br transferred usuefullys tored or disspiated but cannot be created or destroyed .

Question 10

How does a Sankey Diagram work?

Answer 10

Width energy tranansferred 60J
Straigh arrow is useful energy J
bent arrow bdown is wasted energy 20J

Question 11

What is efficency ?

Answer 11

Efficency is a measure of hwo good a device is at ransferrign energy usually from one store to anothe r.
-More efficent a device is , less energywasted
-all devices waste energy so no device hudnred rpecent efficent .

Question 12

Equation for efficeincy ?

Answer 12

Useful output energy / total input energy
times by 100 for percent
NO efficency should be greater than 1 or you have done it wrong .

Question 13

how to imporve efficency

Answer 13

dfriction between moving parts cause heating - lubricae moving parts to reduce frction .
Resistance of wire causes wire to get hot when curent passes throurgh - use wires wilth litle elctrical ressitance ,
air resitance on object ooposting motio - stremamline obect to reduce air resistance ,
sound caused by machinery - tighten loose parts reducing vibratio cutting out nosie .

Question 14

first stage of thermal insualtors rqp ?

Answer 14

Compare effectiveness of different mterials as insulators aim .
-place small beaker isnide a large beaker
-boil water ,a dd 10cm cubed of hot water into smal beaker .

Question 15

second stage of thermal insualtors rqp ?

Answer 15

Use a piece of cardobard as lid for beaker .
-have a hole in lid for thermometer , Place thermometer i hot warer , maing sure bulb of thermomeer is in hot water .

Question 16

third stage of thermal insualtors rqp ?
independant - maetiral
control-volume of water , mass of material
-dependedan - temp of wate r.

Answer 16

Recall starting temp of ater and star tropwach record temp for 3 min for every 15min
repeat experiment with different insualting materials (but betwen small and big beaker) . like bubble wrap and fabric .

Question 17

What are results of the rqp ?

Answer 17

-Coolin g curves
-msot effective isnulitng mterial , water will cool down most slowly with msot effetcing isnulating material (last line ).

Question 18

inevsiage thickness of material .

Answer 18

-repeat experiemnt ut this time using on emaateiral whic is our control as well as sgtart temp
indepenant changin layers (do 2 , 4 y layers)
-more layers of material , mroe slowly water cools , Most effective thermal insulator than fewer layers .

Question 19

The higher the thermal conductivity of a material …

Answer 19

The higher the rate of energy transfer by conduction across that material .

Question 20

One type of insualtion in houses ?

Answer 20

-between brick wall and breeze wall has a caviity - howeert his has a high thermal condcutivity
-so builders put INSULATING MATERIAL between the walls which have a low rhermal conductivity .
-Double glazed windowns also have low thermal conducivity - less energy leavs the house interiori .

Question 21

Another type of insualtion in hosues ?

Answer 21

Loft insultio - low thermal conductivity, reducing rate at which thermal neergy passes thorugh .
-Reduce thermal enrgy transfer forma hosue by using materials with low themral conducitivity ,
Thick walls also reduce rate of thermal energy transfe r.

Question 22

What is a renewable energy source ?

Answer 22

A renewale enegry source is one that is being repelnsihed or can be replenised as it is used .

Question 23

examples of reenwable resources ?

Answer 23

-Wind
Solar
Hydro
Biofuels
Geothermal
.Nuclear

Question 24

Nuclear pwoer

Answer 24

-Used to generate electricity but doesn’t bburn so dont realse greenohsue gases.
–extremley reliable a lot of electricity
-but radioactive waste must be stored for many eyas until it safe to be processed very dangerous for environemnt .
-decomissionign power station mny years , expensive .

Question 25

Bio fuels ?

Answer 25

-Produced from burning plants to produce steam.
-Carbon neutral as it dosen’t add to global warmming , renwable plants gorwn produciing more biomass ,
HOwveer if we use land for growing fuels for crops , could push up price of food

Question 26

Solar Power

Answer 26

Transfer energy from sun by eelctic current ,
-Expensive but good in places that sunny .
unreliable in uk not lawyas sunny .

Question 27

Hydroelectirc power

Answer 27

-dams are built form large reservoirs .
gates can be opeoened to let water in as it does turns turbines and egenerates electricity
can destroy habitats when dams are built .

Question 28

Tidal Power

Answer 28

Relies on seawater building up behind barrer at high tide .
GaaRS WITHIN BARRIER OPEN TO ALLOW WATER IN
HOWEVER THIS CAN DESTROY HABITTS ANFD EXPEENSIVE

Question 29

Wave power

Answer 29

Air is trapped between waves and atrubine , as waves rises and falls it puhses air through turbine .

Question 30

What do nuclear power stations run on ?

Answer 30

NOn renewable
Run oon elemnts uranium and Plutonium

Question 31

Give the three fossil fuels .

Answer 31

-Coal
-Oil
-Natural gas

Question 32

Advantages of fossil fuels .

Answer 32

-reliable , always provide enrgy when we need it .
-release a great deal of energy- aeroplanes ,
-quiet abundant so relativel cheap
-extremly versatile .

Question 33

Disadvanagtges of fossil fuels ?

Answer 33

-Releases a huge amount of Co2 contributes to climate change .
-non renewbal ecanotbe repleished as we use so will run out
-also relases pollutnts like carbon particles and nitrous oxide which is harmful to environemnt .

Question 34

How does power station work ?

Answer 34

-fossil fuels is burned and heats water in boiler .
-Biling water becoes steam and steam turns the turbine .
-The turbine turns the generator and electriciy is produced .
-low pressure steam is condendsed bck into water in cooling towers and water is resued .