Energy and Energy Resources Notes

==Energy is the ability to cause change/the ability to do work.==

\ The ==Work-Energy Theorem states that the amount of energy an object has equals the amount of work done on it.==

\ ==Kinetic Energy is the energy of a moving object:==

  • @@Two factors that affect the kinetic energy of an object are mass and speed.@@
  • Faster−movingobjectshavemorekineticenergythansloweronesbecauseyoudomoreworkonanobjecttomakeitmovefaster.Faster-moving objects have more kinetic energy than slower ones because you do more work on an object to make it move faster.
  • Heavierobjectshavemorekineticenergythanlighterobjectsbecauseyouhavetopush/pullharderontheminordertomakethemmove.Heavier objects have more kinetic energy than lighter objects because you have to push/pull harder on them in order to make them move.

\ ==Potential energy is stored energy for later use.==

Potential energy can take one of three possible forms:

  • ==Gravitational potential energy is potential energy due to the position of an object.==  @@Objects that are higher above the ground have the potential to fall@@ afartherdistancethanobjectsthatareclosetotheground.a farther distance than objects that are close to the ground.   * Example:  %%A book on a shelf could fall to the ground.%%
  • ==Elastic potential energy is potential energy due to the material an object is made out of.==  @@Stretchy or squishy objects have the potential to snap back or recoil when you let go of them.@@   * Example:  %%A stretched rubber band can snap back to its original shape when you release it.%%
  • ==Chemical potential energy is potential energy due to the bonds between atoms of an object.==  @@The energy is released when these bonds are broken.@@   * Example:  %%Food is broken down by your digestive system to provide thermal and kinetic energy.%%

\ ==An object's total amount of energy (potential energy + kinetic energy) is called that object’s mechanical energy.==

\ ==Sound energy is energy carried by objects that vibrate.==  Soundenergycannottravelthroughcompletelyemptyspace.Sound energy cannot travel through completely empty space.

 \n

==Thermal energy is the sum of the kinetic and potential energy of atoms and molecules in matter due to their motion:==

  • ^^Thermal energy is a fancy way of saying “heat energy”^^
  • Hotterobjectshavemorekineticenergy(andfaster−movingmolecules)thancoldobjectsdo.Hotter objects have more kinetic energy (and faster-moving molecules) than cold objects do.

\ ==Electric energy is the energy carried by an electric current.==

\ ==Radiant energy is the energy carried by electromagnetic waves:==

  • ^^Radiant energy is often more commonly called light energy.^^
  • Wecalllight“radiantenergy”becausemostelectromagneticwavesareatwavelengthsandenergiesoureyescannotsee.We call light “radiant energy” because most electromagnetic waves are at wavelengths and energies our eyes cannot see.   * Examplesincludex−rays,microwaves,ultravioletlight,andinfraredlight.Examples include x-rays, microwaves, ultraviolet light, and infrared light.
  • Radiantenergy<strong>can</strong>travelthroughemptyspaces.Radiant energy <strong>can</strong> travel through empty spaces.

 \n ==Nuclear energy is energy stored in the nucleus of an atom.==

\ ==Energy cannot be created or destroyed.  It can only be transformed from one kind into another.  This statement is known as:==

  • ==The Law of Conservation of Energy==
  • ==The First Law of Thermodynamics==

\ %%When you throw or kick a ball into the air, it has a lot of kinetic energy the moment you kick/throw it.%%  @@As it rises, that kinetic energy is turned into potential energy.@@  %%When the ball%% @@reaches its highest point, it stops, and@@ @@all of the kinetic energy has turned into potential energy.@@  %%Then, the ball begins to%% @@fall back down to the ground again@@ %%under the influence of gravity.%%  @@Its potential energy is turned into kinetic energy once again until it reaches the ground.@@

\ @@If you added up the kinetic energy and potential energy of the ball at any point, however, you’d find that the total amount of energy would always be the same.@@  ==This is the Law of Conservation of Energy the total amount of energy of the ball does not ever change.==

\ @@Oftentimes, kinetic or potential energy is turned into thermal energy.  This is because of the presence of friction.@@

\ @@Whenever we transform energy from one kind to another, some of the energy is always turned into thermal energy.@@  ==This thermal energy that we cannot use is known as waste energy.== \n @@Whenever energy is used, some is transformed into useful energy, and some is transformed into waste energy.@@  ==It is impossible not to waste any energy at all.  This statement is known as the Third Law of Thermodynamics.==