Energy and pressure Flashcards
work done, efficiency, transfers, stores, power, pressure
seven energy stores
- kinetic
- chemical
- electrostatic
- elastic
- gravitational potential
- nuclear
- thermal
anything moving has energy in which store
kinetic
anything that would fall if wasn’t supported would have energy in which store
gravitational potential
anything that can release energy by a chemical reaction ( like food and fuels) would have energy stored in
chemical
anything stretched like springs or rubber bands would have energy stored in
elastic
in nuclear reactions, atomic nuclei release energy. which energy store would this be
nuclear
2 charges that attract or repel each other would have energy stored in
electrostatic
what object would have internal or thermal energy store
any object, the hotter it is, the more energy it has in that store
the 4 main energy transfers
- mechanical
- by heating
- by waves
- electrically
electrical energy transfer
work is done by an electric current flowing
mechanical energy transfer
work is done by a force acting on an object ( pushing, pulling, stretching)
waves energy transfer
energy being transferred by waves of light or sound
heating energy transfer
energy being transferred from a hotter object to a colder object
what is the principle of conservation of energy
in a reaction, energy cannot be created nor destroyed, it can only be stored, transferred or dissipated
energy is measured in
joules
anything that is moving has energy stored in the kinetic energy store true or false
true
formula for kinetic energy store of an object
Ek= 1/2 x mv squared
gravitational potential energy store equation
GPE= mass x gravitational field strength (10) x change in height
the higher an object is from the ground, the ____ energy it has in its gravitational potential energy store
more
work done is equal to
energy transferred
mechanical work done formula
mechanical work done= force x distanced moved
( which also equals energy transferred mechanically because work done = energy transferred)
power is the
work done, or energy transferred per unit time
power formula
power= energy transferred / time taken
efficiency formula
useful energy output/ total energy input x100
can a device or process be 100% efficient
no real devices or processes are no
pressure is
the force per unit area
pressure formula
pressure = force / area
unit of power
Watts
2 variables that affect the pressure at a point beneath the surface of a liquid
density
depth
change in pressure between different depths equation
density of liquid x gravitational potential field strength (10) x change in depth
how is pressure measured
in pascals Pa
the larger the area a force is applied over, the ____ pressure the force creates
lower
