P1 - Conservation and Dissipation of Energy Flashcards
What is an energy transformation diagram?
It is a diagram that tracks energy change from one type of energy store to another.
What is the meaning of the word “potential”?
potential - store
What is the mnemonic for remembering energy types?
Most Kids Hate Learning GCSE Energy Names
What are the 10 energy types?
- Magnetic
- Kinetic
- Heat (thermal)
- Light (radiant)
- Gravitational potential
- Chemical potential
- Sound
- Elastic potential
- Electrical
- Nuclear
What are the 4 processes of energy transfer?
- Mechanical - By the action of a force.
- Electrical - By an electrical current.
- Radiation - By Light waves or Sound waves.
- Heating - By conduction, convection, or radiation.
define dissipation of energy
dissipation of energy describes the ways in which energy is wasted/not usefully transferred
law of conservation of energy
it states that energy cannot be destroyed or created, it can only change form.
What is work done?
work done is simply energy transferred
formula for work done
work done (J) = force (N) x distance (m)
define Hooke’s law
Hooke’s law states that the extension of a spring is directly proportional to the force applied
define a closed system
A closed system is where no energy is dissipated through energy transfer
define resolution
resolution is the smallest amount between 2 distinct points
formula for uncertainty
uncertainty = 1/2 x range
mean ± uncertainty
formula for elastic potential energy
elastic potential = 1/2 x spring constant x extension2
Ee = 1/2 ke2
J = 1/2 x N/m x m2
define friction
Friction is a resistive force that slows things down and tries to stop objects that are sliding past each other
What direction does friction act in?
Friction acts in the opposite direction to motion
What is friction named in:
- gases
- liquids
Air resistance
Drag
What is friction caused by?
It is caused by bumps and hollows on a surface
How is heat created by friction?
Heat is created when the bumps of a surface break off
What is a way to reduce the force of friction?
Lubricant, bearings, and rollers
What is a way to reduce air resistance?
Streamlining is the shaping of an item to reduce the force of air resistance (or drag)
define precision
how close results are together
define accuracy
how correct results are
formula for kinetic energy
kinetic energy = 1/2 x mass x velocity2
Ek = 1/2 mv2
J = kg x m/s
define energy efficiency
a measure of how good one device is at changing energy from one form to another
formula for energy efficiency
energy efficiency (%) = (useful energy out / total energy in) x 100
define power
power is the rate at which something transfers energy
formula for power using energy
power = energy or work done / time
P = E/t
W = J / s
formula for power using electrical current
power = current x voltage
P = IV
W = A x V
formula for gravitational potential energy
mass x gravitational field strength (10N/KG) X height or weight x height
