work and energy Flashcards
how to calculate work done
work done = force x distance
true/false
work is being done while standing still and holding a luggage
false
is the amount of work done equal to the amount of energy transferred
yes
what is the SI unit of work
J (joules)
what unit is force and distance in (when calculating work)
force: N
distance: M
what is energy
energy is the capacity to do work
list the types of energy
-kinetic energy
-potential energy
-chemical potential energy
-elastic potential energy
-gravitational potential energy
-nuclear energy
-thermal energy
state the principle of conservation of energy
energy cannot be created or destroyed in any process. It can be converted from one form to another or transferred from one body to another but the total amount of energy in a closed system is constant.
why do things like a bouncing ball come to a stop after a while
the kinetic energy in the bouncing ball was dissipated in other forms such as heat and sound energy.
state the energy conversion in a moving car
chemical potential energy (in petrol) —> kinetic energy (moving car) + heat and sound energy
what are some sources of energy
-fossil fuels
-hydro-electric
-solar energy
-wind energy
-tidal energy
-geothermal energy
-biofuels
why are energy sources like wind and solar energy more sustainable compared to fossil fuels
fossil fuels are a non-renewable source of energy unlike wind and solar energy. Thus, it is not able to be used indefinitely making it an unsustainable source of energy.
what are biofuels made out of
biofuels are made from plant or animal materials
what are the environmental impacts of energy sources
-air pollution
-people have to move away because of construction of hydro electric dams
-noise pollution because of wind turbines + death of birds
