The Law of Conservation of Matter states that matter can change in form as a result of physical and chemical changes

1
Lesson 16

• The Law of Conservation of Matter states that
  matter can change in form as a result of physical
  and chemical changes
• No matter is created or destroyed and the overall
  mass of the matter does not change.

2
Kinetic and Potential Energy

• All energy can be classified into two categories
• A. kinetic
• B. Potential

3
Kinetic and Potential Energy

• Kinetic energy is energy
• resulting from the motion of
• an object
• The amount of kinetic energy
• an object has is determined by the mass of
  the object and the speed of the object.

4
Kinetic and Potential Energy

• Kinetic energy ½ x mass x velocity (2)
• KE ½ mv(2)

5
Kinetic and Potential Energy

• Potential energy is stored
• energy
• An object has potential energy
• because of its position or
• composition

6
Kinetic and Potential Energy

• Potential energy
• mass x height
• PE M x H
• Potential energy
• stored in an object
• can change into
• kinetic energy

7
Energy Transformations

• Energy can be
• transformed or
• changed from one
• form to another
• Energy
• transformations are
• part of your daily life.

8
Energy Transformations

• Plants convert
• electromagnetic energy
• from sunlight into
• chemical energy through
• the process of
• photosynthesis

9
Energy Transformations

• When you eat vegetables,
• you body converts some of
• the stored chemical energy
• into thermal energy to
• maintain your body temperature and mechanical
  energy to enable you to move

10
Energy Transformations

• Chemical energy stored in
• fuels, such as logs, is
• converted to
• electromagnetic energy and
• thermal energy

11
Energy Transformations

• Stars like the sun convert
• nuclear energy into
• electromagnetic energy
• and thermal energy.

12
Energy Transformations

• The energy in vegetables you eat
• is stored in the vegetables as
• chemical energy
• The energy in fuels also is stored
• chemical energy
• This energy is released when the fuels are
  burned

13
The Law of Conservation of Energy

• No matter how energy is transformed, energy
  itself is not made or destroyed.
• Law of Conservation of Energy states while
• energy may change from one
• form to another, energy is neither
• created nor destroyed

14
The Law of Conservation of Energy

• In some energy conversions
• energy may appear to be lost or
• destroyed
• This occurs because energy
• transfers are never completely
• efficient

15
The Law of Conservation of Energy

• When energy is transferred
• from one object to another or
• when an object hits the
• ground
• Some energy is usually
• released as thermal energy
• (heat)

16
The Law of Conservation of Energy

• Friction is responsible for
• this apparent energy loss.
• Friction is present any time
• two objects are in contact
• with one another

17
The Law of Conservation of Energy

• When you roll a ball across a floor, the ball
• comes to a stop because
• of friction between the
• ball and the floor

18
The Law of Conservation of Energy

• A swing pendulum eventually stops because of air
  resistance
• Air resistance is a form of friction that opposes
  the motion of an object moving through air