P1 energy Flashcards
what is a system
a system is a group of objects that energy effects or is stored in for example: a ball rolling to hit a wall
what is the equation for kinetic energy
1/2 * mass * speed^2
what is the equation for elastic potential energy
1/2 * spring constant * extension^2
what is the equation for gravitational potential energy
mass * gravitational field strength * height
what is specific heat capacity
the amount of energy required to raise the temperature of 1KG of a substance by 1 degree
what is the equation for specific heat capacity
energy = mass * specific heat capacity * temperature change
what is power in terms of energy
the rate at which energy is transferred or work is done
what is the equation for power
power = energy transferred/time = work done/time
why does lubrication reduce energy loss
-reduces friction
-less energy is therefore lost through friction
why does thermal insulation reduce energy loss
reduces the amount of useful thermal energy being released and lost
explain thermal conductivity
if a material conducts thermal heat more than heat can be lost more easily through it
eg: thick low conductive walls will trap more heat then thin metal walls
what is efficiency
the ratio of useful work done by the machine etc to the amount of energy inputted into it
what is the equation for efficiency
efficiency = useful energy output / total energy output = useful power input / total power input
how can the efficiency of a system be increased
-reducing waste output
-recycling waste output
name 5 non renewable energy sources
fossil fuels (coal, gas, oil) and nuclear fuel
