P1 - Energy Flashcards
Conservation of energy?
Energy cannot be created or destroyed.
Closed system?
No energy transfers take place out of or into the energy stored of the system.
Total energy is always the same after and before transfers.
Energy transferred equals??
Work done.
Work done?
When a force makes an object move.
Can be used as braking force too.
Work done to overcome friction?
Is transferred as energy to the thermal energy stores of the objects that rub together and to the surroundings.
Why is the GPE store of an object increased?
Because work is done, (when raised up), the work done over comes the gravitational force.
How to calculate the increase of GPE stores of objects going up a slope?
You find the vertical height gained not the distance along slope.
Change in GPE equation?
Change in GPE = mass * gfs * change in height.
Equation for elastic potential energy?
= 1/2 * constant * extension2
Define elastic potential energy?
Energy stored in an elastic object when work is done on the object.
Key words? (Energy dissipation)
Dissipated - spread out
Wasted energy
Useful energy
How can machines be made more efficient?
By reducing the energy they waste (noise, thermal, etc.)
5 Energy stores?
Thermal, chemical, kinetic, gravitational potential, elastic potential
4 Energy transfers?
Heating, electric current, waves, force moving an object
D. Dissipate?
Spread out to the surroundings
