P1 PHYSICS Flashcards
What are 5 types of energy stores?
Kinetic, gravitational potential, elastic potential, chemical, thermal
What is a system?
Fancy word for a single object or group of objects
What happens when a system changes?
Energy is transferred either into or away from the system, between different objects in the system or between types of energy stores
What are closed systems?
Systems where neither matter nor energy can enter or leav. Net change in closed system is always zero.
Describe the energy transfers for boiling water in a kettle
Energy transferred to the ater by heating, into the waters thermal energy store causing its temperature to rise.
How could the kettles heating element and the water together be seen as a two object system?
Energy is transfferred electrically to the thermal energy store of the kettles heating element which transfers energy by heating to the waters thermal energy store
What is work done?
Another way of saying energy transferred
When can work be done?
When a current flows or by a force moving an object
Give an example of work being done
Ball dropped from a height is accelerated by gravity. The gravitational force does work. It causes energy to be transferred from the balls gravitational potential energy store to its kinetic energy store
When is energy transferred to an objects kinetic energy store?
When the object speeds up
When is energy transferred away from the kinetic energy store?
When the object slows down
What does the energy in a kinetic energy store depend on?
The objects mass and speed (heavier and faster = more energy in kinetic energy store)
Give the equation for kinetic energy
Kinetic Energy = 1/2 x mass x velocity^2
What are the units of mass?
Kilograms, Kg
What is the units of velocity?
Metres per second squared, (m/s)^2
