alex 7 science unit 2 topic 1-3 quiz Flashcards
energy
The ability to do work or cause change.Energy has many forms, all of which measure the ability of an object to do work on or change another object.In other words, there are different ways that an object can possess energy.
mechanical energy
kinetic
potential
different forms
Thermal, or heat energy Chemical Energy Electrical Energy Electrochemical Energy Electromagnetic Energy (light) Sound Energy Nuclear Energy
potential energy
Potential energy is energy due to position or stored energy. Potential energy is also called gravitational potential energy.
example
By stretching a rubber band, you give it potential energy. A vase on a shelf has stored potential energy. A football being held by a quarterback has potential energy until it is thrown and it turns into kinetic energy.
Kinetic energy
Kinetic energy is the energy of motion. Kinetic energy is measured by how much is work done to put an object in motion or to rest.
example
A basketball player has kinetic energy. The movements that she does show the energy that is being displayed while she is moving. When you are running, walking, or jumping, your body is exhibiting kinetic energy.
what has both potential and kinetic energy
A waterfall has both kinetic and potential energy. The water at the top of the waterfall has stored potential energy. Once the water leaves the top of the waterfall, the potential energy is changed into kinetic energy.
Conservation of Energy
Energy cannot be created or destroyed; it can only be changed from one of form of energy to another form. The amount of energy stays the same.
Temperature
How hot or cold it is. Measured in degrees Celsius.
Heat
The amount of thermal energy, measured in joules or J.
example
A cup of hot tea has heat energy in the form of kinetic energy from its particles.
comparing heat and temp
example
A swimming pool at 30°C is at a lower temperature than a cup of tea at 80°C.BUT
the swimming pool contains more water, so it stores more thermal energy or heat.
comparing heat and temp
example
The small beaker of water boils first The large beaker contains more water and needs more thermal energy or heat to reach 100°C.
tnt how is energy displayed in it
Chemical energy stored in it is transferred to the surroundings as thermal energy, sound energy and kinetic energy.
drums how is energy displayed in it
Sound energy can be transferred to your eardrum as kinetic energy (movement energy).
battery how is energy displayed in it
The battery transfers stored chemical energy as electrical energy. The electrical energy is transferred to the surroundings by the lamp as light energy and thermal energy (heat energy).
The Law of Conservation of Energy
Energy is always conserved, it is never “lost” or “wasted“.Some energy transfers are useful and some are not.
