Energy%20and%20Its%20Forms

1
Energy and Its Forms

• 15.1

2
Energy and Work

• Work is done when a force moves an object through
  a distance.
• Energy is the ability to do work.
• Energy is transferred by a force moving an object
  through a distance.
• Work is a transfer of energy.

3
Energy

• Many forms of energy can be classified into two
  general types
• Kinetic Energy
• Potential Energy

4
Kinetic Energy

• The energy of motion is called kinetic energy.
• The kinetic energy of any moving object depends
  upon its mass and speed.
• Kinetic Energy (KE) ½ mv2

5
Example

• A 0.10kg bird is flying at a constant speed of
  8.0 m/s. What is the birds kinetic energy?
• KE ½ mv2

6
Potential Energy

• Potential energy is energy that is stored as a
  result of position or shape.
• Two forms of potential energy are
• Gravitational potential energy
• Elastic potential energy

7
Gravitational Potential Energy

• Potential energy that depends upon an objects
  height is called gravitational potential energy.
• An objects gravitational potential energy
  depends on its mass, its height, and the
  acceleration due to gravity.
• Potential Energy (PE) mgh

8
Practice

• A diver at the top of a 10.0 m high diving
  platform has a mass of 50.0 kilograms. What is
  her potential energy?
• PE mgh

9
Elastic Potential Energy

• The potential energy of an object that is
  stretched or compressed is known as elastic
  potential energy.
• EX springs, guitar strings, bike shocks

10
Forms of Energy

• The major forms of energy are mechanical energy,
  thermal energy, chemical energy, electrical
  energy, electromagnetic energy, and nuclear
  energy.

11
Mechanical Energy

• The energy associated with the motion and
  position of everyday objects is mechanical
  energy.
• Not limited to machines.
• Mechanical energy is the sum of an objects PE
  and KE.