WHAT IS ENERGY? Introduction to Energy!
•What is energy? What comes to mind when you hear the word energy?
Do you picture running, leaping, and spinning? How would you define energy?
•Energy is an object’s ability to cause change. You might not realize it, but you have a large amount of energy. In fact, everything around you has energy, but you only notice it when a change takes place. All objects, including leaves and desktops have energy. Two Types of Energy…
We can categorize energy into two categories potential and kinetic. Potential Energy (Energy of Position)
• Potential energy is the energy stored in an object based on its position. An
object can have energy even though it is not moving. For example, a rock
sitting still at the top of a hill has potential energy. It has potential to cause
change. The higher the rock is above the ground, the greater the potential
energy will be. Potential energy is also affected by the mass of an object.
The greater the mass of an object the greater the potential energy the
object will have. So, a boulder will have greater potential energy than a
home-feet-article-1.1595700 Kinetic Energy (Energy of Motion)
• Kinetic energy is the energy an object has due to its motion.
When an object is still it no longer has kinetic energy. For
example, remember that rock sitting at the top of the hill?
When the rock starts rolling down the hill it has kinetic energy.
When the rock gets to the bottom of the hill and stops, it is no
longer in motion therefore it no longer has kinetic energy, the
energy has been converted back into potential energy. Recap…
• So, Potential Energy = Stored energy and the object is
NOT moving. Rock SITTING at the top of a hill.
• And Kinetic Energy = Energy that is in MOTION. Rock
ROLLING down the hill. Let’s take a look at an Example!
• Roller coasters are a great example of potential and kinetic energy being converted back and forth…
• http://www.teachersdomain.org/asset/mck05_int_roll ercoaster/
• Potential and kinetic energy Forms of Energy
• There are eight forms of energy. Each of these can be categorized into either potential or kinetic energy.
• These eight forms can change from one form of energy to another…but you will talk about this next week!
• Let’s take a look at the eight forms and figure out whether or not it can be categorized as kinetic or potential. Mechanical Energy
• The movement of objects from one place to another. These objects move when a force is applied to them.
•Examples: Boiling water (convection), sun heating the earth Radiant Energy
•Travels in waves and is produced when a force causes an object to vibrate or move in place.
• Fun Science
• Light and Sound
• Types of Energy Chemical Energy
•Energy stored in the bonds of atoms and molecules. •Examples: Food, matches, batteries Gravitational Energy
• Movement of electrical charges.
• Examples: Toaster, lamp, hair dryer Atomic (nuclear) Energy
• Energy stored in the nucleus of an atom. Energy is released when the atoms are combined, Fusion, or when the atoms are split apart, Fission. Categorizing the forms of Energy
POTENTIAL (Stored energy) KINETIC (energy in motion)
• Nuclear • Sound
• Chemical • Radiant
• Thermal • Gravitational