Energy exists in different forms.

Energy Kinetic energy Potential energy Vocabulary to know Energy Kinetic energy Potential energy

Remember All substances are made of matter Matter has mass and is made of tiny particles (atoms)

Remember Matter has both chemical and physical properties Matter can exist in different physical states. It can be changed physically or chemically Gravity is the force that objects exert on each other because of their mass

Energy Energy is the ability to cause change All forms of energy cause changes to occur Energy of wind causes a flag to flutter Electrical energy causes a light bulb to get hot and glow

Electromagnetic energy FORMS OF ENERGY Mechanical energy Sound energy Chemical energy Thermal energy Electromagnetic energy Nuclear energy

Mechanical energy The energy that moves objects Mechanical energy has the ability to do work

Mechanical energy Mechanical energy is the energy which is possessed by an object due to its motion or due to its position. Mechanical energy can be either kinetic energy (energy of motion) or potential energy (stored energy of position).

Mechanical energy

Mechanical energy

Sound energy Sound results from vibration of particles ina solid, liquid or a gas. Sound CANNOT travel through empty space

Sound energy Sound is a vibration When something makes a noise it is vibrating, and this causes air molecules around it to vibrate too. These vibrations are transmitted through the air, to our ears, where we perceive them as sound.

Chemical energy Energy that is stored in the chemical composition of matter The amount of chemical energy in a substance depends on the types and arrangement of atoms in the substance

Chemical energy

Thermal energy The total amount of energy from the movement of particles in matter Remember that matter is made of atoms and atoms combine to make molecules Atoms and molecules in matter are ALWAYS moving The energy of this motion in an object is the object’s thermal energy Ex. of thermal energy are stoves and matches

Electromagnetic energy Transmitted through space in the form of electromagnetic waves These waves can travel through empty space Ex. Are visible light, x-rays and microwaves The sun also releases electromagnetic energy

Nuclear energy The center of an atom-its nucleus is the source of nuclear energy This energy holds the nuclear particles together When an atom’s nucleus breaks apart, or when the nuclei of two small atoms join together, energy is released This keeps the Sun burning (the nuclear energy released from the fusing of small nuclei to form larger nuclei)

Nuclear Energy

THE TWO GENERAL TYPES OF ENERGY: KINETIC AND POTENIAL All forms of energy can be described in terms of either potential or kinetic

KINETIC ENERGY ENERGY IN MOTION Depends both on an object’s mass and the speed at which it is moving Remember : all objects are made of matter, and matter has mass. The more matter an object contains, the greater it’s mass

INCREASES AS MASS INCREASES Kinetic Energy INCREASES AS MASS INCREASES

Kinetic Energy THINK ABOUT THIS: What would have more kinetic energy, a bowling ball or a soccer ball moving at the same speed?

INCREASES AS SPEED INCREASES Kinetic Energy INCREASES AS SPEED INCREASES

Kinetic Energy THINK ABOUT THIS: If two identical bowling balls were rolling at different speeds, would the faster bowling ball have more K.E. or would the slower moving bowling ball have more K.E.?

Potential Energy The stored energy that an object has due to its position or chemical composition

Potential Energy The most obvious form of potential energy is the potential energy that results from gravity Gravity is the force that pulls objects toward Earth’s surface

How can you tell the difference between kinetic and potential energy? Potential or Kinetic? How can you tell the difference between kinetic and potential energy?

Potential and Kinetic Energy

Potential or Kinetic? Bending a spring back and letting it go gives the spring first potential and then kinetic energy When a book falls or a spring straightens, potential energy is released this potential energy is changed to kinetic energy when motion occurs

Potential or Kinetic? Chemical energy, such as energy stored in food is also a form of potential energy This energy depends on the chemical composition of the food It is the result of the atoms, and the bonds between them, that make up the molecules in food When these molecules break apart, and their atoms get rearranged through a series of chemical changes, energy is released

Why is chemical energy a form of potential energy? Think about It Why is chemical energy a form of potential energy?