# What is energy and what are the different forms?

## Presentation on theme: "What is energy and what are the different forms?"— Presentation transcript:

What is energy and what are the different forms?
SPS7a: Identify energy transformations within a system. Essential Question: What is energy and what are the different forms?

Energy : the ability to do work Examples of energy are all around you.
Energy is connected to work. Energy is measured in the same unit as work, joules (J). We are more used to the unit of energy called the calorie calories = 1 kilocalorie, which is written as Calorie. A 100 Calorie cookie has 100 kilocalories of energy.

__________ Potential Energy
Potential Energy, PE: Stored energy The energy of position. Examples: spring, stretched rubber band, any object that could fall. Gravitational __________ Potential Energy Energy of an object because of its height. Example: waterfall

Potential Energy It has the ability or potential to give that energy back by doing work. Potential energy does not always have to be mechanical energy. Example: energy stored in food. This energy is chemical. The energy is stored in the food and released when the food is broken down through digestion

Which hurts more, a bowling ball dropped on your foot from a height of
Which hurts more, a bowling ball dropped on your foot from a height of .10 m or from 3 m? 3 m -> had more PE

Kinetic Energy, KE: Energy of motion
The faster an object moves the more kinetic energy it has. Kinetic energy is directly related to the velocity of an object Kinetic energy depends on both mass and velocity.

Bowling ball – more mass – more energy
Which hurts more when dropped on your foot, a ping pong ball or a bowling ball at 5 m/s? Bowling ball – more mass – more energy a tennis ball at 2m/s or 20 m/s? 20 m/s – more speed – more energy

Find all the PE stored in this situation.
INQUIRY Find all the PE stored in this situation.

ENERGY IS CONSERVED!! Which means energy is not Created or destroyed
The Law of Conservation of Energy ENERGY IS CONSERVED!! Which means energy is not Created or destroyed Energy can be transferred from one object to another and can be changed from one form to another.

Roller coaster Example
PE=250J At the top: KE= Coaster has all PE Total energy 250J

PE= KE= 250J At the lowest point: all KE Total energy 250J

KE= 125J PE= 125J In the middle: Some KE and some PE Total energy 250J

Where does the roller coaster get its PE to begin with?
WORK! The chain does work to get the coaster to the top of the first hill.

What can you say about the total energy of the system?
D E F B INQUIRY Describe the energy at the labeled points. What can you say about the total energy of the system?

Work-Energy Cycle: Work, heat, sound, etc. Work PE KE

work Man does_____lifting weight work PE ______ turns into ____

Man releases weight, ___ turns into _____
PE KE

work heat sound Weight hits ground, does _____ driving
stake into ground, also generating _____ and ______ sound

Where do the mallets have PE? Where is WORK being done?
INQUIRY Where do the mallets have PE? Where is WORK being done? Where do the mallets have KE?

Where does this energy come from? INQUIRY What happens to the energy as he is falling? Where does all the energy go in the end?

What energy transformations do you see in this clip?
INQUIRY What energy transformations do you see in this clip?

What kind of energy transformations do you see happening here?
INQUIRY What kind of energy transformations do you see happening here?

What energy transformations do you see in this clip?
INQUIRY What energy transformations do you see in this clip?

Quick Quiz (Vocabulary)
1. ________ can be defined as the ability to do work. 2. The energy of motion is called_______. 3. The internal motion of the atoms is called_________. 4. The nucleus of an atom is the source of ________. 5. __________ is energy of position.

What energy transformations do you see in this clip?
` INQUIRY What energy transformations do you see in this clip?

Forms of Energy Mechanical energy: Matter that is in motion has energy. Mechanical Energy is any object that is moving or could move. Examples - water in waterfall, blood flowing through your blood vessels.

Forms of Energy Thermal Energy (heat): All matter is made of tiny particles called atoms that are constantly moving. The internal motion of the atoms is called heat energy. The faster the particles move, the more thermal energy is produced. Heat energy often comes from friction or light hitting an object.

Forms of Energy Chemical energy: Energy exists in the bonds that hold atoms together. This energy is called chemical energy. When fuel is burned, chemical energy is released and converted into thermal energy. Ex- start a fire in a charcoal grill; digest food

Forms of Energy Electrical energy: Energy associated with moving electrons. These moving electric charges have the ability to do work. Ex- power lines; electric motors; electric lights Electromagnetic energy: energy of moving photons or waves of light. Ex- visible light; lasers; infrared; ultraviolet; x-rays; radio waves; microwaves.

Forms of Energy Nuclear energy: the nucleus, or center of an atom is the source of nuclear energy. Nuclear energy is released when lightweight nuclei collide at high speeds and fuse. Nuclear energy is released in the form of heat, light, sound, and mechanical energy. Nuclear energy is most concentrated form of energy. All energy untimately comes from nuclear energy.

Other Forms of Energy Sound Energy- waves of energy moving through matter Gravitational Energy- any object that could fall, roll, or slide down

What energy transformations do you see in this clip?
INQUIRY What energy transformations do you see in this clip?

Questions to Answer 1. What is energy?
2. Can energy be transferred from one object to another? Explain. 3. What are different forms of energy? 4. Why is energy measured in same unit as work?