P 1 Flashcards
How can you transfer energy ?
By heating , waves , an electric current , or when a force moves on objects.
What are some examples of chemical energy stores ?
Fuels , foods , or the chemicals found in batteries . The energy is transferred during chemical reactions .
What are kinetic energy stores ?
They describe the energy an object has because it is moving
What are gravitational potential energy stores ?
Used to describe the energy stored in an object because of its position .
What is the elastic potential energy store ?
Describes the energy stored in a springy object when you stretch or squash it .
What is the thermal energy store ?
Describes the energy a substance has because of temprature .
How can you show energy transfers ?
A flow diagram
What are 5 types of energy transfer ?
Heating
Electrical
Light
Sound
Mechanical
How can you investigate if the total amount of energy stays the same ?
A simple pendelum .
What is a closed system ?
A system in which no energy transfers take place out of or into the energy stores of the system .
What is a system ?
An object or a group of objects .
What is an open system ?
Allows the exchange of energy and matter to or from its surroundings .
What does the conservation of energy state ?
It states that energy cannot be created or destroyed .
What are the seven stores of energy ?
Gravitational
Kinetic
Chemical
Nuclear
Electrostatic
Magnetic
Thermal
What is the definition of work done ?
The amount of energy transferred to the object is equal to the work done on it .
What is the equation for work done ?
Force x distance
What is friction ?
A contact force that opposes the direction of movement when two surfaces are in control .
How do you work out the change of gravitational potential energy ?
Mass x gravitational field strength x height
What is the equation for kinetic energy ?
1/2 x mass x speed squared
How do you work out the elastic potential energy of an object ?
1/2 x spring constant x extension squared
What is useful energy ?
Energy transferred to where it is wanted in the way that it is wanted .
What is weight measure in ?
Newtons
What is energy measured in ?
Joules
How do you work out input energy ?
Useful output + energy wasted
How do you work out efficiency ?
Useful output energy transferred / total input energy supplied
What is the definition of power ?
The rate at which energy is transferred
What is power of an appliance measured in ?
Watts and kilowatts
What is the equation for power ?
Energy / time
