energy stores

Question 1

types of energy stores?

Answer 1

magnetic 
internal
chemical
kinetic 
electrostatic
elastic potential
gravitational potential 
nuclear

Question 2

what is magnetic

Answer 2

the energy stored when attractions poles are pulled apart
or
repelling poles are pushed together

Question 3

what is internal

Answer 3

total kinetic energy and potential energy of particles in a substance

Question 4

what is chemical

Answer 4

energy stored in chemical bonds \

in between molecules

Question 5

what is kinetic

Answer 5

energy of moving object

Question 6

what is elastic pot

Answer 6

energy stored when object stretched or squashed

Question 7

what is gravitational

Answer 7

energy of an object at height

Question 8

what is nuclear

Answer 8

energy stored in nucleus of atom

Question 9

what is electrostatic

Answer 9

when repelling charges pushed together
or
attracting charges are pulled apart

Question 10

energy transfers

Answer 10

when system changes
energy is transferred
into or away from system

Question 11

closed system

Answer 11

no energy enters or leaves system

net change is 0

Question 12

how to transfer energy

Answer 12

mechanically
electrically
heating
radiation

Question 13

what is work done?

Answer 13

energy transferred by

a force moving an object through a distance

Question 14

work done formula

Answer 14

work done (J) = force(N) x distance (m)

Question 15

how do falling objects transfer energy?

Answer 15

energy from gpe store transferred to kinetic store

Question 16

kinetic energy formula

Answer 16

Ek (J)= 1/2 mass (kg)x speed(m/s) ^2

Question 17

gravitational pot formula

Answer 17

Ep(J)= mass (kg) x gfs (N/kg) x height (m)

Question 18

elastic pot formula

Answer 18

Ee = 1/2 spring constant(N/m) x extension ^2 (m)

Question 19

conservation of energy principle

Answer 19

energy can be transferred usefully / stored // dissipated but not created or destroyed

Question 20

energy dissipation

Answer 20

energy being wasted

stored in not useful way

Question 21

smartphone example

Answer 21

energy transferred usefully from chemical store in battery to electrical energy
some dissipation into thermal energy
light comes from smartphone emitted light radiation

Question 22

what is power

Answer 22

power is the rate of work done
or
energy transfer rate

Question 23

power formula

Answer 23

power ( W) = energy transferred (J) / time (s)

Question 24

efficiency

Answer 24

how good a device is at transferring energy input to useful output

efficient = waste less energy 
inefficient = most energy wasted

Question 25

efficiency formula

Answer 25

useful energy transferred / total energy supplied x 100

measured in j

Question 26

how to improve efficiency

Answer 26

lubricate them
insulating them
streamlined shape

Question 27

where is energy wasted

Answer 27

thermal energy store
no device is 100% efficient
electric heaters are
transferred to useful thermal store

Question 28

electric kettle

Answer 28

energy heating water
wasted= thermal energy heating kettle
infrared lost to surroundings

Question 29

hair dryer

Answer 29

thermal energy heating air that blows out

wasted = sound radiation

Question 30

light bulb

Answer 30

light radiation given out

infrared and heat lost to surroundings

Question 31

tv

Answer 31

sound and light

internal energy heating tv set