energy (paper 1) Flashcards
is energy ever used up?
no
list the 8 energy stores
thermal
kinetic
GPE
EP
chemical
magnetic
electrostatic
nuclear
kinetic energy equation
Ek = 0.5mv^2
define doing work
transferring energy from one form to another
a builder pushes a wheel barrow a distance of 5.0m across flat ground with a force of 50N. how much work was done by the builder
Wd=Fxd
Wd=50N x 5.0N
Wd=250J
what is the gravitational field strength?
9.8N/kg
define kinetic energy
the energy an object has when its moving at a constant velocity
define renewable
resource that won’t run out in our lifetime
define conduction
where vibrating particles transfer energy to neighbouring particles
define convection
where energetic particles move away from hotter to cooler regions
define non-renewable
resource that damages the environment and will run out one day
list the three main non-renewable fossil fuels
coal
oil
(natural) gas
list the 7 renewable energy sources
sun (solar)
wind
water waves
hydro-electricity
bio-fuel
tides
geothermal
explain how energy is transferred as a ball falls to the ground
GPE to kinetic
if energy is transferred to an object’s kinetic energy store what happens to its speed?
speed increases
what kind of energy store is energy transferred to when you compress a spring
EPE
definition of the specific heat capacity of a material
the energy required to raise one kg of the material by one degree Celsius (°C)
does a high thermal conductivity mean there is a high rate of energy transfer
yes
give 4 ways to prevent unwanted energy transfers in a home
windows and doors
floor insulation
insulating pipes
solid wall insulation
define the term system
an object or a group of objects
a cyclist allows his bike to roll down a hill without pedalling. he applies his breaks towards the bottom making it come to a stop. applying breaks causes brakes to warm up. describe the energy transfers that have occurred and state the forces doing work that cause each of these energy transfers
- gravitational force does work on bike causing energy to be transferred from the GPE store of the bike to its KE store
- friction force does work between brake pads and wheels causing energy transfer from bikes KE store to thermal store of the brake pads
state 2 disadvantages of solar panels
efficiency is low
only produces power in the day
state the law of conservation of energy
- energy cannot be created or destroyed
- only can be transferred from one form to another
As the parachutist falls, gravitational potential energy and the kinetic store of the parachutist decrease. Energy is still conserved. Explain how energy is still conserved.
- as parachutist falls there is friction between the air and the parachutist and the parachute
- energy is transferred to the thermal energy store of the parachute and parachutist
