Topic 2.3: Energy, Work and Power Flashcards
What is energy?
Energy is the ability to do work
What is the principle of conservation of energy?
Energy can not be created or destroyed
What are the 10 forms of energy?
- Kinetic energy
- Gravitaional potential energy
- Elastic (strain) energy
- Electromagnetic wave energy
- Sound energy
- Heat (thermal) energy
- Chemical energy
- Electrical energy
- Nuclear energy
- Internal (kinetic and electric potential) energy
Which of the forms of energy can be stored?
- Gravitational Potential
- Chemical
- Elastic
- Nuclear
- Electrostatic
- Internal
- Kinetic
What is energy transformations?
Energy cannot be created or destroyed but it can be transferred between different forms or stores of energy
What are energy tranformation methods?
Transfer methods include using forces (called mechanical work), electrical currents (electric work), mechanical (mass) waves (eg ropes, water, sound) and electromagnetic (including light and infra-red heat raiation)
What are the key things needed in a energy transfer diagram?
The key thing is to include the input and outpu energy forms
What are some additional things that can be included in energy transfer diagrams?
Significant intermediate energy forms as well as significant energy “losses” usually heat (thermal) energy can also be included
What is thermal energy dissapation?
In any energy transformation, ie an event or process, energy tends to become more spread out or dissapated
In simple terms, all energy ends up as heat (thermal) energy that spreads out so it is unable to be used for any process
What is the explaination for energy loss through heat with FRICTION?
Rubbing materials together causes their molecules to move faster gaining internal energy and temperature increases
Once the temperature of the materials is higher than the surroundings, the material will radiate heat energy until the temperature of the material and surroundings are the same
What is the explaination for energy loss through heat with ELECTRIC CURRENTS?
Moving electrons hit metal atoms (ions) making them move faster, gain internal energy, increasing temperature and heat energy is radiated to the surroundings
What is work?
Work is done whenever one form of energy is converted into another form of energy
What is the formula that describes the relationship between force, distance and work?
Work = Force * distance
What is the formula for the energy stored by a spring?
Ep = 1/2 F * Δx
not in data booklet
What is the WORK-ENERGY equation?
F = 1/2 mv²
not in data booklet
