Energy and transformation Flashcards
(37 cards)
What is the definition of energy?
-The capacity to do work or to produce change
What form of measurement is used to measure energy?
One “Joule” or “J” represents the energy needed to lift an object weighing 1 Newton (N) to the height of 1 meter. An object that weighs 1 N has a mass of 100 grams. The formula is:
Joules= Newtons x Meters
Grams= Newtons x 100
Newtons= Joules
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What are the different forms of energy and their sources?
- Solar energy-the sun
- elastic energy-wire spring
- Electrical energy-power station
- thermal energy-fire
- radiant energy-electric light bulb
- chemical energy-living cell
- mechanical energy-moving vehicle
- wind energy-wind
- sound energy-sound
- hydraulic energy-waterfall
- nuclear energy-nucleus of atom
What is thermal energy?
What are two factors affecting thermal energy?
Thermal energy is the energy that comes from the random motion of particles that make up a substance.
1) the higher the temperature of a substance, the faster the particles are moving, the higher the thermal energy
2) the more particles in a substance, the more collisions occurring, the more thermal energy
What are examples of work or change accomplished by thermal energy?
- melting of snow by the heat of the sun (solid)
- production of water vapour by the boiler of a steam engine in order to move the train (liquid)
- the lifting of a hot air ballon into the sky by the burners heating of air inside the ballon (gas)
What is radiant energy?
Radiant energy is the kind of energy that is contained in and transported by electromagnetic waves. (Any waves part of the electromagnetic spectrum).
Ex: listen to the radio, cook with a microwave, get a tan, get an X Ray
How does the wavelength depend on the energy?
When a wavelength is shorter, the energy frequency is higher
When a wavelength is longer, the energy frequency is lower
What do electromagnetic waves do in energy?
They transfer energy from one place to another.
Does energy creation exist?
No, no energy can be created or destroyed, only transformed
What is chemical energy?
It is the energy stored in the bonds of a molecule.
- An atom is the smallest particle of matter, and cannot be divided
- A molecule is a group of two or more atoms held together by chemical bonds
Does chemical energy do work or create change?
No, but to get the energy out, it must be broken. So the more bonds a molecule has, the stronger it is
What is photosynthesis?
When the suns energy is transformed into chemical energy and is stored in the bonds of a sugar molecule (glucose)
What is cellular respiration?
It helps living organisms use the energy stored in sugar molecules so they can grow, move and think. Cellular respiration converts nutrients into adenosine triphosphate
What is mechanical energy?
The energy that results from the speed of an object, its mass and its relationship to its surroundings.
(It is the energy of motion that does the work)
How does speed affect mechanical energy?
Mechanical energy increases with speed.
Ex: the damage caused by a car crash with the car going 100km/h is much greater than a crash at 20km/h
How does mass affect mechanical energy?
The more mass, the greater the mechanical energy.
Ex: a car crash with a truck does more damage than one with a small car
How does the relationship to surrounding affect mechanical energy?
An object higher up has more energy than objects lower to the ground
What is energy transformation?
Transformation of energy is the changing of energy from one form to another.
Ex: when a log burns, some of the chemical energy stored in the wood is transformed into a radiant energy (light) and thermal energy (particle movement).
How does a lamp undergo energy transformation?
How does a plant undergo energy transformation?
LAMP: electrical energy to radiant and thermal energy
PLANT: during photosynthesis it changes from radiant energy to chemical energy
What is energy transfer?
It is the movement of energy from one place to another.
Ex: with a burning log, the energy transfers from the log as heat, to the room.
What’s the difference between energy transformation and energy transfer?
Energy transformation changes the energy’s form, while energy transfer moves the energy from one place to another.
How does thermal energy transfer?
It transfers between 2 places whose temperatures are different.
Thermal energy always travels from the place with the hugh3st temperature to the place with the lowest temperature.
What are the three mechanisms of thermal energy transfer?
Conduction, convection, and radiation
What is conduction?
It is heat flowing through a stationary material. The atoms and molecules of the material aren’t flowing, but the heat is flowing through the vibrations of those atoms.
