p1 Flashcards
name all of the energy types
magnetic, kinetic, heat, light, gravitational potential, chemical, sound, elastic potential, electrical, nuclear
(most kids hate learning g c s e energy names)
what is the law of conservation of energy?
energy can be transferred or dissipated. it can not be created or destroyed.
what is work done?
work is defined as the amount of force needed to move an object a certain distance
it is measure of an energy transferred to or from an object which allows it to be moved
what’s the equation for work done?
w = f x s
w - work done ( J, joules or newton -metres, Nm)
f - force (N, newtons)
s - distance (metres,m)
what’s the equation for gravitational potential energy?
Ep = mgh
Ep - GPE
m - mass (kg)
g - gravitational field strength (9.8N/kg on earth)
h - height (m)
what’s the equation for kinetic energy?
Ek = 1/2mv^2
Ek - kinetic energy (joules J)
m - mass (kg)
v - velocity (m/s)
what’s the steps to follow when doing an equation?
- find variables
- choose equation
- check units
- substitute
what’s the relation between GPE and Ek
if an object goes straight up into the air Ek is converted to GPE
in science we assume that this energy transfer is 100% efficient
the opposite would be true for an object falling to the floor
F = ke
Force(N) = spring constant (Nm) x extension (m)
what’s the equation for elastic potential?
Ee = 1/2ke^2
Ee - elastic potential energy (J)
k - spring constant (Nm)
e - extension/ compression (m)
what is power?
power is the amount of energy transferred (work done) by an object per unit of time
what’s the equation for power?
power = energy/ time
power - watts (W)
energy - (J)
time (seconds, s)
what happens to the energy wasted in a lightbulb
it’s transferred to surroundings by heating
why is it useful to have both a wind turbine and a fossil fuel generator 2 reasons
sometimes there’s no wind
when there is wind less fuel is burned
what is a non renewable energy resource
an energy resource that can’t be replenished as it’s used
why does the temperature of a heater change quickest after the heater is switched off
there is a bigger temperature difference between the water and the surrounding air so the transfer of energy is faster
why would fitting an insulating jacket to heater be beneficial
water stays hot for longer
so heater is on for less time
so cost of jacket can soon be recovered from
name all the non renewable energy resources
- oil
- coal
- natural gas
- nuclear
name the 6 renewable energy resources
- tidal energy
- solar energy
- wind energy
- geothermal energy
- biomass energy
- hydroelectric energy
name the energy transfer or tidal barrage
kinetic to electrical
(water is trapped as tide comes in. turbines spin)
name the energy transfer of hydroelectric dams
gravitational potential energy to electrical
name two disadvantages of nuclear energy
- produces harmful radioactive waste that needs to be buried for a long time
- high cost of commissioning and decommissioning
what is u - value
how effective a material is as an insulator
how is the u value of a house affected by increasing the amount of insulation?
u-value decreases
name four advantages of nuclear energy
- no carbon dioxide so does not contribute to GHE
- no sulphur dioxide produced so does not contribute to acid rain
- reliable
- more energy produced than the same mass of fossil fuels
four advantages of solar energy
- renewable
- no carbon dioxide produced so does not contribute to the GHE
- no sulphur dioxide produced so does not contribute to acid rain
- no fuel cost
name one disadvantage of solar energy
unreliable - doesn’t work when it’s cloudy or at night
name four advantages of wind energy
- renewable
- no carbon dioxide so does not contribute to GHE
- no sulphur dioxide produced so does not contribute to acid rain
- no fuel cost
name three disadvantages of wind energy
- unreliable - wind does not always blow so electricity is not always produced
- noise and visual pollution
- takes up a lot of land
name three advantages of biomass energy
- renewable
- a way of disposing waste
- carbon neutral - carbon dioxide produced is balanced by carbon dioxide absorbed whilst producing it
name a disadvantage of biomass energy
takes up a lot of land and consumes resources that are needed for food production
name four advantages of geothermal energy
- renewable
- no carbon dioxide so does not contribute to GHE
- no sulphur dioxide produced so does not contribute to acid rain
- no fuel cost
name four advantages of hydroelectric energy
- renewable
- no carbon dioxide so does not contribute to GHE
- no sulphur dioxide produced so does not contribute to acid rain
- no fuel cost
name two disadvantages of geothermal energy
- expensive to drill underground to reach hot rocks
- power stations can only be built near natural hot springs
name three disadvantages of hydroelectric energy
- expensive to build dams / reservoirs
- destroys habitats
- can lead to flooding
name five advantages of tidal energy
- renewable
- no carbon dioxide so does not contribute to GHE
- no sulphur dioxide produced so does not contribute to acid rain
- no fuel cost
- reliable - tide does not depend on weather
name a disadvantage of tidal energy
destroys aquatic habitats and kills aquatic animals
give two advantages of using a data logger and temperature probes over a thermometer
- higher resolution
- reduced risk of misreading the instrument
give two reasons why it would not be economical to connect houses in a mountainous area to the national grid
- high cost of installing overheard power lines or underground cables or pylons
- high cost as very long cables are needed
when would a thermometer be better to use over a temperature probe and data logger?
when you only need to measure the start and end temperature
what does energy efficient mean?
a higher proportion of the total energy input is usefully transferred
