EQ: What is energy and how can it be transformed? Unit 3: Eighth Grade

EQ: What is energy and how can it be transformed? FORMS OF ENERGY EQ: What is energy and how can it be transformed?

Energy When wind moves a house, or even a leaf, it causes a change. In this case, the change is in the position of the leaf. Scientifically, work is when a force (a push or a pull) moves an object over a distance. The ability to do work or cause change is called energy.

Energy Energy is NEVER created or destroyed! It can only be stored or transferred. The Law of Conservation of Energy

Two Categories of Energy Potential Energy Kinetic Energy The energy stored in an object because of its position Examples: a bike at the top of a hill, a glass of water on a table. The energy an object has due to its motion If it’s not moving, it does not have kinetic energy Examples: a ball rolling, a person walking,

Potential Energy The more mass an object has, the more potential energy it has. The higher an object, the more potential energy.

Potential Energy Converted into Kinetic Energy When stored energy begins to move, the object now transfers from potential energy into kinetic energy.

Kinetic Energy The energy of a moving object. "Kinetic" means movement! When stored energy is being used up, it is making things move or happen.

Kinetic The faster the object moves, the more kinetic energy is produced. The greater the mass and speed of an object, the more kinetic energy there will be.

Types of Energy In addition to being categorized as either potential energy or kinetic energy, energy can be further broken down into subgroups called types. The types of energy we will focus on are: Mechanical energy Chemical energy Thermal energy Electrical energy Electromagnetic energy Nuclear enery

Mechanical Energy Mechanical energy is the energy of movement. This type of energy is the most common because it deals with the motion and the position of an object. It is a combination of the object’s potential and kinetic energy. Examples: Throwing a ball Pulling a book off a shelf Pedaling a bicycle

Chemical Energy Almost anything you touch, see or taste is composed of chemical compounds. The chemical compounds are made up of molecules and atoms Bonds between the atom and the molecules hold chemical compounds together. Those bonds have a chemical energy. When bonds in chemical compound break, some new chemical compounds are able to form. When this happens, chemical energy is able to be released. Chemical energy is stored in the matches you light up, the food you eat and even in the cells in your body.

Thermal Energy All objects are made of particles called atoms and molecules. Thermal, or heat energy, is the total potential and kinetic energy of the particles in an object Because these particles are constantly in motion, they have kinetic energy. The faster the particles move, the more kinetic energy they have. Faster moving = higher temperature Heat is only produced if the particles touch EX: the sun’s thermal energy heats our atmsophere

Electrical Energy Electrical energy is energy of electric charges. Depending on whether the charges are moving or being stored, this electrical energy can also be a form of kinetic and potential energy. Multiple charges that are moving make up an electric current. Electric currents have charged particles (usually electrons) moving through a conductor. Metals are good conductors because their electrons can move freely, and plastics are bad conductors (insulators) because their electrons can't move freely An example of electrical energy can be lightning, it carries electrical energy. Anything that runs on battery is electrical energy, and electrical lines have electrical energy

Electromagnetic Energy Electromagnetic energy travels in waves. In theses waves, the waves have some electrical properties and some magnetic properties. Some examples for electromagnetic energy would be: a microwave X-rays are electromagnetic too. Some other forms of electromagnetic energy are ultraviolet radiation, infrared radiation, and radio waves

Nuclear Energy Nuclear energy is a type of potential energy because it is stored energy in the nucleus of an atom. The only way to release the energy from the nucleus is to cause a nuclear reaction. Two types of nuclear reactions are nuclear fission and nuclear fusion. Nuclear fission occurs when a nucleus splits. Nuclear power plants use fission reactions to produce electricity. Nuclear fusion usually happens when the nuclei of atoms come together. An example of nuclear fusion is the sun, it happens continuously and releases unthinkable amounts of energy

EQ: What is energy and how can it be transformed? Transforming Energy EQ: What is energy and how can it be transformed? https://www.youtube.com/watch?v=0ASLLiuejAo

Energy Transformations Most forms of energy can be transformed into other forms. A change from one form to another is called an energy transformation. Some energy transformations involve single transformations, and others involve many transformations

Types of Energy Transformations Single Transformation Multiple Transformation Sometimes, one form of energy needs to be transformed into another to get work done. Example: toaster Starts with electrical Transforms to thermal. Electrical thermal Often, a series of energy transformations is needed to do work. For example: striking a match Starts as: mechanical energy Transformation #1 thermal energy. The thermal energy causes the particles in the match to release. Transformation #2: stored chemical energy, which is transformed to : Transformation #3: thermal energy and final transformation is to: Transformation #4: The electromagnetic energy you see as light Mechanical thermal chemical thermal electromagnetic

Types of Energy Transformation One of the most common energy transformations is the transformation between potential energy and kinetic energy. In waterfalls such as Niagara Falls, potential energy is transformed to kinetic energy. The water at the top of the falls has gravitational potential energy. As the water plunges, its velocity increases. Its potential energy becomes kinetic energy. Velocity: speed in a given direction (north, south, east, west, up, down, left, right, etc)

Types of Energy Transformations When does the train on this roller coaster have the MOST potential energy? AT THE VERY TOP! The HIGHER the train is lifted by the motor, the MORE potential energy is produced. At the top of the hill the train has a huge amount of potential energy, but it has very little kinetic energy.

Types of Energy Transformations As the train accelerates down the hill the potential energy is converted into kinetic energy. There is very little potential energy at the bottom of the hill, but there is a great amount of kinetic energy.

Types of Energy Transformations When does the train on this roller coaster have the MOST kinetic energy? When is it moving the fastest? When does it have the LEAST potential energy? At the bottom of the tallest hill! http://www.pbslearningmedia.org/asset/mck05_int_rollercoaster/

Law of Conservation of Energy If a top is set into motion, will the top remain spinning forever? No, it will not. Why? What happens to the mechanical energy? Is it destroyed? Again, the answer is no. Why?

Law of Conservation of Energy The law of conservation of energy states that when one form of energy is transformed to another, no energy is destroyed in the process. According to the law of conservation of energy, energy cannot be created or destroyed. The total amount of energy is the same before and after any transformation. If you add up all the new forms of energy after a transformation, all of the original energy will be accounted for.

Law of Conservation of Energy So what happened to the energy in the top? As the top spun, it encountered friction with the floor and friction from the air.

AP: Energy Transformations Card Sort Lay the cards out on the table Using your graphic organizers and the anchor notes, match each picture to the correct energy transformation Collaboration and consensus-building expected When you finish, politely call me to your table to check your work!