paper 1 textbook Flashcards
(20 cards)
Define a black body
a theoretical object that absorbs 100% of the radiation that falls on it
a perfecr black body would not reflect or transmit anybraeiation and would also be a perfect emitter of radiation
4 methods of energy transfer
-heating
-waves
-electricity
-forces (mechanical work)
disadvantages of nuclear fission (as a nonrenewable energy resource)
produces nuclear waste (dangerous, difficult and expensive to dispose of, stored for centuries before it is safe to deposit or
requires a nuclear power plant (expensive to build/run/shut down (decomission)
advantages/disadvantages of solar
adv:
can be used in remote places
very cheap to run once installed
no pollution/greenhouse gases produced
disadv:
supply depends on weather
expensive to buy and install
cannot supply large scale demand
advantages/disadvantages of hydroelectric
adv:
low running costs
no fuel costs
reliable and supply can be controlled to meet demand
disadv:
expensive to build hydroelectric dams
floods a large area behind the dam, destroying habitats
results in greenhouse gases production from rotting vegetation
adv/disadv of tidal energy
adv:
predictable supply as there are always tides
can produce large amounts of electricity
no fuel costs
no pollution/greenhouse gases
disadv:
-tidal barrages: can change marine habitats + harm animals, restrict access and can be dangerous for boats, are expensive to build and maintain
-cannot control supply
-supply varies depending on time of month
adv/disadv wave energy
adv:
low running costs
no fuel costs
no pollution/greenhouse gases produced
disadv:
floating generators (change marine habitats and can harm animals, restrict access and can be dangerous fpr boats, are expensive to build/install and maintain
-dependent of weather
cannot supply large scale demand
adv/disadv of geothermalnenergy
-adv:
low running costs
no fuel costs
no pollution
disadv:
expensive to set up
only possible inna few suitable locations around the world
sdv/disadv of wind
adv:
low running costs
no fuel costs
no pollution/greenhouse gases produced
disadv:
supply depends on weather
large amounts of land needed to generate enough electricity forbkarge scale demand
can produce noise pollution for nearby residents
adv/disadv of biofuels
adv:
can be carbon neutral, reliabel and supply can be controlled to meet demand
disadv:
expensive to produce
growing requires a lot of land and warer that could be used for food production
-can lead to deforesation as forest are cleared for growing biofuel cropa
what kind of current does mains suppky
alternating
what do step up transformers do
increases potential difference and decreases current
how can you protect urself against irradiation
-maintain distance from source
-limiting time near source
-shielding from the radiation
nuclear radiation in medicine
EXPLORINGNINTERNSL ORGANS USING A TRACER
gamma emitting tracers are injected
gamma cameras can then create an image showing where tracer has gone
OR
CONTROLLING ORNDESTROYING UNWANTED TISSUE
-ionising radiotheraoy destroys certain cancers
-gamma rays pass into body to destroy the tumour
problem:healthy tissue may also be damaged as radiation passes into the body
name sources of background radiation
-natural sources like rocks and cosmic rays
-nuclear weapons and nuclear accidents
Describe what happens in a van der graaph generator
-electrons pass from top plastic roller onto moving belt
-at bottom, electrons pass off belt and are transferred to earth
-overtime top region becomes positively charged
-dome acts like a store of positive charge by allowing it to spread out
-by touching dome, you are now positive,y charged
-hairs are all positively charged so they repel eachother and move apart
potential energy definition
intermolecular forces and chemical bonds between particles
define internal energy
energy stored in a system by particles
it is the total kinetic energy and potential energy of all the particles that make up a system
solid to gas
sublimation
list risks of exploring internal organs using tracer
- tracer must emit radiation that can pass out of the body and be detected (gamma or beta)
- tracer must not be stringly ionising to minimise damaging the body tissue
- tracer must not decay into another radioactive isotope
- tracer must have a short half life so it is not present in the body for a long period
