1. Energy exists in different forms.

2. Energy Kinetic energy Potential energy
Vocabulary to know
Energy
Kinetic energy
Potential energy

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

4. 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

5. 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

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

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

8. 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).

9. Mechanical energy

10. Mechanical energy

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

12. 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.

13. 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

14. Chemical energy

15. 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

16. 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

17. 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)

18. Nuclear Energy

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

20. 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

21. INCREASES AS MASS INCREASES
Kinetic Energy
INCREASES AS MASS INCREASES

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

23. INCREASES AS SPEED INCREASES
Kinetic Energy
INCREASES AS SPEED INCREASES

24. 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.?

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

26. 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

27. 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?

28. Potential and Kinetic Energy

29. 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

30. 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

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