Energy Flashcards
Name the 8 stores of Energy
Gravitational Potential
Elastic potential
Electrostatic
Kinetic
Sound
Nuclear
Chemical
Heat (Thermal)
Name the 5 ways energy can be transferred
Mechanically (moving due to force)
Electrically (a charge moving through pd)
By heating (energy from a warmer to a colder object)
Radiation (eg energy from the sun)
Light or sound waves
The conservation of energy principle
Energy can be transferred usefully, stored or dissipated but can never be created or destroyed
What is the difference between an open and closed system
In an open system energy can be transferred with the world outside the system so it can lose or gain energy.
Closed systems do not. Their energy is only transferred within the system so the overall net change of energy is always 0
What is the equation for Kinetic energy (with units)
KE = ½mv²
Kinetic energy = 0.5 x mass × speed²
KE = Joules
Mass = Kilograms
Speed = metres per second
With the same amount of energy but different masses, out of two objects, which would have more kinetic energy
The object with a larger mass
What is the difference between weight and mass
Mass is how much we weigh, whereas weight is our mass multiplied by the rate of gravitaional pull
What is the formula for Gravitational Potential Energy
Ep = M G H
gpe= mass × gravitational field strength × height
Ep = Joules
Mass = Kilograms
Gravitational field strength = Newtons per kilogram
Height = metres
What happens to the GP(E) when an object is falling
It is transfered in Kinetic Energy
Name elements with low thermal conductivity
Plastics and Fluids
Name a group of elements with high thermal conductivity
Metal
Explain convection
Takes place in fluids
Move around much faster when provided with energy
Warm air will rise (as they’re less dense)
Then cool and fall
Then rise again in a convection current
Radiation
Energy can be transfered within a vacuum (without other particles)
Energy is carried by Infared waves
What ways are there to reduce heat loss in the home (4)
Sealing the house closed (foam seals and closing curtains)
Thick walls with low conductivity material to prevent conduction
Cavity walls (two layers of brick with a gap in between) but instead of a gap there should be insulated material with tiny air bubbles to prevent conduction and convection simultaeneously
Double glazed windows. Two layers of window with a gap in between
What are the 2 definitions of Power
Power is the rate at which energy is transferred
P= E/T
Power = Energy ÷ Time
Power= Watts
Energy= Joules
Time = Seconds
————————–OR————————-
Power is the rate at which work is done
P = W / T
Power = Work ÷ Time
Power = Watts
Work done = Joules
Time = Seconds