p1-energy

Question 1

what is specific heat capacity

Answer 1

the amount of energy required to raise the temperature of 1kg of substance by 1 degrees

Question 2

formula for shc

Answer 2

change in thermal energy = mass x shc x change in temp

triangle footprint

Question 3

kinetic energy formula

Answer 3

Ek = 1/2mv(squared)

= 1/2 mass x speed

Question 4

gravitational potential energy formula

Answer 4

Ep = mgh

= mass x gravity field strength x height

Question 5

elastic potential formula

Answer 5

Ee = 1/2ke(squared)

= 1/2 spring constant extension

Question 6

conservation of energy and power principle

Answer 6

energy can be transferred usefully, stored or dissipated but never created or destroyed

Question 7

what is power

Answer 7

rate of energy transfer

rate of doing work

Question 8

what is power measured in

Answer 8

watts

Question 9

power equation

Answer 9

p = energy transferred or work done / time

Question 10

what is a powerful machine

Answer 10

one that can transfer a lot of energy in a short space of time

Question 11

where does conduction occur

Answer 11

mainly solids

Question 12

what is conduction

Answer 12

vibrating particles transfer energy to neighbouring particles

Question 13

where does convection occur

Answer 13

mainly liquids and gases

Question 14

what is convection

Answer 14

energetic particles move from hotter to colder region s, transferred by heating the thermal store of the liquids or gases

Question 15

what happens during convection

Answer 15

warmer, less dense particles rise leaving the cooler denser particles below

Question 16

how to reduce unwanted energy transfers

Answer 16

lubrication
insulation
double glazing
thick walls

Question 17

what does lubrications do

Answer 17

reduces friction between objects surfaces

Question 18

how to improve efficiency

Answer 18

insulation
streamlining
lubrication

Question 19

formula for efficiency

Answer 19

useful output transfer/power output
———————————
total input transfer/power output

Question 20

where does most wasted energy go

Answer 20

thermal store

Question 21

true or false

some devices are 100% efficient

Answer 21

FALSE

Question 22

non renewable energy

Answer 22

coal
oil
gas

Question 23

renewable energy

Answer 23

solar
wind
water waves
hydroelectric 
tides 
biofuel
geothermal

Question 24

benefit of non renewable

Answer 24

reliable

Question 25

drawback of renewable

Answer 25

unreliable