Science - Planet Earth - energy transfer and sources booklet

Kinetic energy

Means movement. You can have rotational and linier types of this

potential energy

Means stored. You can have gravitational elastic and magnetic versions of this

heat energy

can also be called thermal. It causes items to warm up

Light Energy

travels through any transparent material. makes objects visible to us

Electrical energy

moving electrons. helps to power many items in the home and portable appliances

Nuclear energy

Come from the nucleus. (The centre) of an atom

chemical energy

stored in bonds (joints) between atoms that make up substances around us

sound energy

vibrating air particles caused by vibrating objects e.g. Loud speaker, vocal chords, drum

what is the energy conservation law

energy can't be created or destroyed but can be transferred from one type to another.

What does this mean

The total amount of energy you have in a system is always the same.

What is energy measured in

Joules (J)

define "efficiency"

ability to accomplish something with the least waste of energy

what's the most efficient light bulb

LED

what makes a lightbulb inefficient

Little light and much heat, heat is not needed so this is a waste of energy

10% of light and 90% of heat is this efficient or ineffecient

inefficient

are heat and temperature the same thing

no

what is heat energy measured in

Joules (J)

what is temprature

a measurement of how hot something is measured in degrees Celsius. (ºC)

to format an energy change what would you do

you would write the energy down draw an arrow next to it and write the energy convert next to it

for a normal plastic car what would the energy changer be

kinetic (no change)

for clackers, what would the energy changer be

kinetic→ sound

for a poper, what would the energy changer be

potential → kinetic

what's the unit of Joules

J

what is suggested when using the word heat

increase and decrease

can heat energy move from place to place

yes

give an example

from cold water tub to a tin metal cup that holds boiling water

what is conduction

the process heat uses to flow through a thermal conductor.

what is a thermal conductor

something that allows heat to flow through them easily

an example of a good conductor

metal

why does metals feel cold to touch

because they conduct heat away from your hand easily

what's a thermal insulator

something that does not allow heat to flow through them easily.

an example of good thermal insulators

non metals e.g. polystyrene

why does polystyrene feel hot in your hand

because it stops your hand from loosing thermal energy

what happens to water when its boiled to a certain level

it boils

what temperature level does water boil at

100 degrees Celsius

what direction does heat travel

upwards and never down

what does the experiment with the icecube inside a tube and water show us.

that glass and waters are poor conductors of heat. this also shows that thermal energy never travels down

in the experiment with the metal rod and pins with wax, where does heat move from

from hot to cold.

why did the wax on the metal rod melt

because the rod was metal and metal is a good conductor. heat moves from hot to cold, so the wax at first was cold and the part of the rod on top of the flame was hot.

what is conducton

the movement of heat energy by particles hitting each other and passing this energy from one particle to the next

what are the tree types of heat traansfer

conduction, convection and radiation

why is convection and conduction different than radiation

because conduction and convection need material to travel, unlike radiation that doesn't rely on anything to travel through

what materials do convection need to travel

fluids (liquid and gas)

What materials do conduction need to travel

solids

what is convection

its the movment of heat energy by moving particles, hot particles move up and cold ones down

whats is the flow called

convection current

what form of heat transfer is used in a radiator

conduction

how does the sun heat travel to us

through radiation

what is another word for empty space

vacume

how does fire spread

through convection and radiation

what do silver surfaces do to heat

reflects most of it and takes little in

what do black surfaces do to heat

adsorb heat in

what directions do heat energy rays travel, in radiation

straight lines

are bright and light surfaces good radiatores

no

are dark and dull surfaces good radiators

yes

what surfaces absorb/don't absorb heat

do = rough surfaces

don't = smooth surfaces