energy:

Question 1

7 main food groups:

Answer 1

dairy
carbohydrates
fat
vitamins
minerals
protein
water

Question 2

kj and joules?

Answer 2

1 kj=1000 joules
more kj a food contains=more heat given off

Question 3

cellular respiration:

Answer 3

process by which organisms break down sugar and turn it into energy through cells.

Question 4

practiacal example to know how much energy food contains?

Answer 4

record starting temperature of the tube of water and when food is completely burned place it on the heat mat and record the final temperature of the water above the fire. work out the temp increase to find out which food has the highest energy. from this we learn the chemical energy stored in the the molecular bonds is released as heat and light. the heat given off can be measures in kj more heat a food contains , the more energy it contains. an example of cellular respiration.

Question 5

joules:

Answer 5

standard unit of energy

Question 6

how do you find out how much energy is stored in food per gram:

Answer 6

e.g cupcake has 250 kj per 100 grams
how much kj does it have per 11 grams?
250 divided by 100=2.5
2.5 times by 11 grams=27.5

Question 7

law of conservation of energy:

Answer 7

energy before= energy after
shows energy cant be created or destroyed
only transferred and changed from one form to another

Question 8

combustion equation:

Answer 8

process of burning something
fuel+oxygen=carbon dioxide+water

Question 9

define fuel:

Answer 9

something you can burn and get energy from

Question 10

types of energy:most wasted energy from their:

Answer 10

kinetic
thermal
chemical
chemical stored
gravitational potential
elastic potential
electric
sound light nuclear
thermal energy energy mostly wasted and builds up a lot in our enviroment

Question 11

define efficiency:

Answer 11

something you pay total energy divided by useful energy times 100
washing machine-useful energy 600 total energy 700
600 divided by 700 times 100 to get it to a percent

Question 12

thermal energy:

Answer 12

energy stored in an object

Question 13

temperature:

Answer 13

measure of how hot or cold an object is

Question 14

bigger/smalller object mass=

Answer 14

bigger the mass the more enrgy particles stored inside but more temperature if less mass as particles join together and in a bigger mass their more spread apart

Question 15

when an object heated its particles..

Answer 15

gain kinetic energy=more vibrations-causing heat

Question 16

thermal energy of a substance depends on?

Answer 16

its mass, specific heat capacity and temperature change
q=m times c times delta triangle

Question 17

4 ways energy transfer:

Answer 17

radiation
conduction
evaporation
convection

Question 18

radiation:

Answer 18

also known as infrared radiation
all thing emit out and give out ir
speed of light travels thru waves-electromagnetic waves
hotter-more ir emitted
doesnt need particles to work

Question 19

eg of radiation:

Answer 19

heat from sun, microwaves, x-rays

Question 20

conduction:

Answer 20

energy transfering thru particles, making them vibrates-an increase in heat so then the heat rising to top
metals are good thermal conductors
eg alluminium, magnesium
only solids conduct heat as fixed particles so can pass through it easily

Question 21

eg of conduction:

Answer 21

metals are good thermal conductors

Question 22

thermal conductors and insulators:

Answer 22

conductors= materials that easily allow energy to transfer through it
insulators= materials taht don’t allow energy to transfer thru it’
water, coat, sand, vaccum, wood

Question 23

convection:

Answer 23

process which energy is transferred through heated fluids
hot air rises at top
cold air then sinks
cycle repeats
like in tea or a room with heating

Question 24

convection eg:

Answer 24

tea, air

Question 25

equalibrium:

Answer 25

balanced forces

Question 26

warm/cold air density:

Answer 26

warm air less dense as partciles move quickly causing an expansion and a distance between them rather than the density in cold air which moves slowy so closer together and more compact

Question 27

dense:

Answer 27

particles closely compacted in substances

Question 28

difference between the three energy transfers:

Answer 28

radiation-travels thru waves doesn't need particles to occur convection- only works with fluids, hot air rises and cold air sinks conduction- only works with solids hot air transferred causing vibrating-rise to top

Question 29

fossil fuels and eg:

Answer 29

non renewable sources meaning they will run out eventually coal, natural oil, gas

Question 30

why are fossil fuels so important:

Answer 30

formed millions of yrs ago from things that didnt rot so if we use it irresponsibly we wont have any left and we cant make more of it like that shabash all done

Question 31

hydrogen and define fuel:

Answer 31

hydrogen-expolsive type of fuel fuel-something you can burn and get energy from

Question 32

how is coal made:

Answer 32

trees get trapped underground more layers appear-causing pressure=sedimentray rocks etc. coal produced

Question 33

how is oil and gas made?

Answer 33

plants and animals remains fall underground in ocean remains get trapped underground for millions of years forms oil and gas through a chemical/natural rection and collected thru pipes eg .nordic pipe in russia

Question 34

how thermal power stations transfer energy through the energy stored in fossil energy to generate electricity:

Answer 34

water put in a furnace boiler converted to steam and connected in wires through a generator travelling thru pylons for electricity for homes.

Question 35

power:

Answer 35

how much energy transferred per second like light

Question 36

power units:

Answer 36

watts (w) 1kw=1000 watts lightbulb has 70w burns 70 joules every second

Question 37

EPT triangle equation:

Answer 37

energy=power times time power=energy divivded by time time=energy divivded by power

Question 38

equation to calculate electricty used:

Answer 38

watts times hours times 1kw/ph

Question 39

work:

Answer 39

energy transferred

Question 40

how do you find out how much work done:

Answer 40

efd trinagle

Question 41

EFD triangle equations:

Answer 41

energy-force times distance distance=energu divivded by force forcce=energy didvivded by distance

Question 42

simple machine:

Answer 42

something which makes a job easie by reducing the force required for it

Question 43

distance in eqautions:

Answer 43

if distance in meters convert cm to meters divivde cm by 100 - metres metres times 100-cm

Question 44

eg of a simple machine:

Answer 44

can opener

Question 45

lever:

Answer 45

a bar that rests and moves around a pivot like a seesaw

Question 46

eg of a lever

Answer 46

seesaw can opener

Question 47

force multiplier:

Answer 47

when a small force applied to one end produces a big force

Question 48

more energy you put in=

Answer 48

more energy you get out

Question 49

example of levers;

Answer 49

wheel barrow scissors bottle opener can opener pilers

Question 50

conduction practical:

Answer 50

drawing pins stuck with vaseline bunsen burner each pin falls one by one bc metals are good thermla conductor allows energy to transfer thru it so yh.

Question 51

convection practical:

Answer 51

potassium magante VII crystals in cold water bunsen burner underneath rises to top .