Energy Flashcards
What happens when a system changes?
There are changes in the way energy is stored
calculation of kinetic energy
kinetic energy (J) = 0.5 x mass (kg) x speed squared (m/s)
the calculation for the gravitational potential energy gained by raising an object above ground level
gravitational potential energy (J) = mass (kg) x gravitational field strength (N/kg) x height (m)
the amount of elastic energy stored in a stretched or compressed spring can be found with the equation:
Ee (J) = 0.5 x spring constant (N/m) x extension ^2 (m)
the equation for power (energy transfer)
energy transferred/ time
equation for power (word done)
work done / time
what is wasted energy caused by?
unwanted energy transfer
How can unwanted transfers be reduced ?
lubrcation- reduces the friction that produces heat
tightening any loose parts - prevents unwanted vibration that wastes energy as sound
thermal insulation - resuces heat loss
What is thermal conductivity?
a measure of how well a material conducts energy when it is heated.
What does the rate of cooling depend on?
the thickness and thermal conductivity of the walls
what is special heat capacity?
the amount of energy required to raise the temperature of one kilogram of the substance by 1 degree celsius
what is internal energy?
the total kinetic and potential energy of all the particles that make up a system
what is the result of doing work on a system
it increases the energy stored in a system
How does heating change the energy in a system
by increasing the energy of the particles within it
as energy increases……
(what happens to the state and the temperture)
it will either increase the temperature or produce a change of state
