P-1 Energy Flashcards
What is the law of conservation of energy
The law of energy conservation is that energy cannot be created nor destroyed
What happens when a system changes
Energy is transferred
What is meant by work done
Work done is the total amount of energy transferred
What is a closed system
A closed system is a system where energy or matter can neither enter nor leave. The total transfer is always zero
What is a kinetic energy store
- Anything that is moving has energy in its kinetic energy store
- Energy is transferred to this store when an object speeds up. It is removed when an object slows down
- IT depends on an objects mass and speed - greater the greater the store
What is the formula for Kinetic energy store
E(k)= 1/2MV2
where
Energy= 1/2 Mass x speed2
What is meant by gravitational potential energy
- Lifting an object in a gravitational field requires energy
- This causes a transfer of energy to the the gravitational potential energy of the object. The higher- the higher the store
- Dependant on mass, height and strength of gravitational field
What is the equation in gravitational potential energy
E(p)= mph
Where
G.P.E= Mass x height x gravitational field strength
What is the relationship between G.P.E and Kinetic energy as an object falls
- For a falling object with no air resistance
Energy lot from G.P.E = Energy gained in kinetic energy
What is Elastic potential energy
- Stretching or squashing an object causes an energy to transfer energy to its Elastic potential store
- This is directly proportionate until the limit of proportionality is exceeded
What is the equation for Elastic potential energy
E(e) = 1/2 ke2
where
Elastic potential = 1/2 spring constant extension 2
What is specific heat capacity
- Specific heat capacity iOS the aunt of energy needed to raise the temperature of 1kg of substance by 1oc
- it is how hard something is to heat up
What is the equation for specific heat capacity
^E = mc^0
Where
Change in thermal energy = Mass x Specific heat capacity x Temperature energy §
What is power
- Power is the rate of energy transfer or rate of doing work
- Power is measured in Watts
- 1 Watt = 1 joule of energy transferred per second
What are the equations for power
P=E/t where Power= Energy/time
P=W/t where power = Work done/ time