Electricity & Radiation
what is a system - a system is a object or a group of objects that interact
what are the different types of energy stores - kinteic, chemical, thermal, gravitational potential,
magnetic, elctrostatic, elastic potetntial, nuclear
what does the principle of conservation of energy state - that the amount of energy always
remains the same, energy cannote be destroyed or created, it only moves from one system to
another
how can energy be transfered - light, sound and electricity
formula of kinetic energy - KE=1/2mv^2
formula of elastic potential energy - Elastic potential energy (J) = 1/2 x Spring constant (N/m) x
Extension² (m) (spring constant is stiffness)
formula of gravitational potential energy - GPE = mgh
what is work - the amount of force needed to move an object a certain distance (some like this
type shi, amount of force a distance has or som)
formula of work done - Work done (J) = force (N) x distance (m)
what is power - the rate at which energy is transfered or work is done
what is formula power - csm power = energy transfered or work done/ time
what is specific heat capcity - the amount of energy required to heat the temperature of one
kilogram of a substance by one degree celcius
what is the formula of specific heat capacity - Change in energy = mass x specific heat capacity x
temp change
, what does dissipate mean - to dissipate means to scatter in all direction
what does it mean when energy dissipates - it means we cannot get it back, the enrgy has spread
out and heat up the surondings
how can we reduce the energy disiptaition - design generators that dont disipate energy, design
cars thata re fuel efficent, streamlined, and lubricated parts...
how reduce energy disiptaiton in home - chimneys allows thermal energy to transfer upstairs yk
wall small so less area to heat, more thermal condutive, more thicker, and difference between
inside and outside
loft insulation and carpets, double glazing means leave a gap in between window or some
shi
what is efficen - way of expression the proportion of energy that is usefully transferered in a
process
formula of efficiency - useful output (energy) or (power output) / total (power output)(energy
transfer)
what is formula of work done - work done = force x distance how to reduce friction -
using wheel or lubricatns
how reduce air resistantce - slow travel, steamlining
how does a macheine increase efficency - a macheine can be a rope, this acts as a force multiplier
allowing to lift heavier weight with less force, this means that the men have to use small force
and save energy and time and safe yk
what are non renewable energy sources - energy soruces that will run out as there is not a finitite
reserve that can replenish (gas, oil fossil fuel