Energy Flashcards
Energy Conversion
Energy can be changed from one form to another. Changes in the form of energy are called energy conversions.
Transducers
Transducers change energy from one form to another
States of energy
- The most common energy conversion is the conversion between potential and kinetic energy.
- All forms of energy can be in either of two states:
+ Potential
+ Kinetic
Kinetic and potential energy
Kinetic Energy is the energy of motion.
Potential Energy is stored energy.
Properties of Kinetic energy
- The energy of motion is called kinetic energy.
- The faster an object moves, the more kinetic energy it has.
- The greater the mass of a moving object, the more kinetic energy it has.
- Kinetic energy depends on both mass and velocity.
Kinetic energy formula
K.E. = mass x velocity
2
Properties of Potential energy
- Stored chemically in fuel, the nucleus of atom, and in foods.
- Or stored because of the work done on it:
+ Stretching a rubber band.
+ Winding a watch.
+ Pulling back on a bow’s arrow.
+ Lifting a brick high in the air.
Gravitational potential energy
Potential energy that is dependent on height is called gravitational potential energy.
Elastic potential energy
Energy that is stored due to being stretched or compressed is called elastic potential energy.
Gravitational energy formula
G.P.E. = Weight X Height.
G.P.E = m X g X h
kinetic energy conversions in the case of a pendulum
AT MEAN POSITION
P.E=ZERO
K.E= MAXIMUM
AT BOTH THE EXTREMES
P.E=MAXIMUM
K.E= ZERO
The Law of Conservation of Energy
Energy can be neither created nor destroyed by ordinary means.
It can only be converted from one form to another.
If energy seems to disappear, then scientists look for it – leading to many important discoveries.
Efficiency
- Efficiency is a measure of how good a device is at changing energy from one form to another.
- All devices waste energy, so the efficiency of a device is never 100%.
Efficiency formula
Useful energy output / Total energy input
