Exploring Energy

What is it? The ability to do work Work = Force X Distance

Work & Energy

Energy can be classified as either: Potential – stored energy Kinetic – the energy of motion

Kinetic Energy 2 The energy of motion Kinetic energy = Mass X Velocity2 2 Or KE = ½ mv2

How many joules of kinetic energy could he give to a ball? Rodger Maris swung a bat which had a mass of 2 Kg at a velocity of 45 m/s. How many joules of kinetic energy could he give to a ball?  

Real World Application - NASA and SCIENCE!

Potential Energy Energy that is stored and held in readiness

Elastic Potential Energy Potential energy associated with objects that can be stretched or compressed

Gravitational Potential Energy Potential energy that depends on height Equal to the work done to lift it Gravitational potential energy = Weight × Height Gravitational potential energy = Mass × Gravitational acceleration × Height GPE = m × g × h or Wt × Ht

Potential Energy to Kinetic Energy Transfer

Kinetic & Potential Energy

Law of Conservation of Energy The conservation of energy is a fundamental concept of physics. The amount of energy remains constant and energy is neither created nor destroyed. Energy can be converted from one form to another (potential energy can be converted to kinetic energy) but the total energy within the domain remains fixed.

Seven Forms of Energy

7 -Forms of Energy Mechanical – movement of parts Sound – movement of sound waves Chemical – produced by chemical reactions Electrical – movement of electrons Radiant – movement of light waves Thermal – movement of molecules Nuclear Energy – energy from splitting atoms

Mechanical Energy Movement of parts.

Sound Energy Movement of sound waves.

Chemical Energy Produced through a chemical reaction.

Batteries – Stored Potential Energy - Chemical are all over the place -- in our cars, our PCs, laptops, portable MP3 players and cell phones. A battery is essentially a can full of chemicals that produce electrons.

Electrical Energy. Movement of electricity. occurs naturally (as in lightning) or is produced (power plant)

Radiant Energy LIGHT ENERGY Movement of light waves. Can be Solar energy: energy from the sun.

Thermal Energy Movement of molecules

energy from splitting atoms Nuclear Energy energy from splitting atoms

Conserving Energy and Fossil Fuels

Energy Conversion A change from one form of energy to another Most common conversion – Potential Energy to Kinetic Energy

Friction Friction converts mechanical energy to thermal energy Motion of the atoms or molecules increases

Einstein’s Theory of Relativity Energy can sometimes be created by destroying matter. Nuclear reactions – huge amounts of energy are produced by destroying tiny amounts of matter. Energy and matter together are always conserved.