equations Flashcards
7 energy stores
thermal
gravitational potential
magnetic
nuclear
kinetic
elastic potential
chemical
5 energy pathways
heating
light waves
sound waves
electrical current
mechanical
specific heat capacity (words)
amount of energy required to raise 1kg of material by 1°C
specific heat capacity method
- measure mass (top pan balance)
- measure initial temp (thermometer)
- connect ammeter in series and voltmeter in parallel
- insert immersion heater into material
- measure the time (stop clock)
- connect power supply and record the current and potential difference
alpha
2 protons 2 neutrons
beta
fast moving electron
gamma
high frequency EM wave
why do we repeat investigations
reduce random error
calculate a mean
spot anomalies
uncertainty
range/ 2
thermistors being special
when their temperature is low they have a high resistance and don’t let current pass though (resistance decreases as temp increases)
direct current
electrons only flow in one direction (battery)
alternating current
constantly changes direction (plug)
source of direction potential difference
battery
a source of alternating potential difference
mains electricity
live wire
brown, carries alternating potential difference from the supply
earth wire
yellow/ green, safety wire to stop the circuit becoming live
neutral wire
blue, completes the circuit (casing)
national grid
system of cables and transformers
national grid
- power released from power station
- makes its way to step up transformer
- SUT dramatically increases pd
- this reduces current, collisions, resistance, energy lost through heat
- power goes into step down transformer
- SDT decreases potential difference
- this increases current so consumer can safely use
renewable
energy source that can be replenished
renewable energy sources
solar, hydroelectric, wave, wind, tidal
non- renewable energy resources
fossil fuels (coal, oil, gas)
nuclear radiation
energy being given off by the nucleus
half life
the time it takes the number of radioactive nuclei in a sample to half
contamination
happens when you take radioactive material inside your body or if it is on your skin
irrigation
happens when there is radioactive material outside ur body that can reach you in waves
(induced) fission (4 marks)
a slow moving neutron is fired at a
uranium nucleus (1)
uranium nucleus becomes unstable (2) and splits into 2 daughter nucleus (3)
3 neutrons gamma waves and energy is also released (4)
define fusion
combining 2 light nuclei to make one larger nuclei and mass is converted into energy through E=mc^2
