1. Mechanical Energy Energy and Environment by Toossi

2. Energy and Power Energy could be in the form of heat or work Heat is thermal energy Work is mechanical energy Power is the rate at which work is performed Energy and Environment by Toossi

3. Units SI vs. US System of units (m, kg, s) vs. (ft, lb, s) Force (N) Energy (1 N.m = 1 J) 1 kJ = 1,000 J; 1 MJ=1,000,000 J Also expressed as barrel of oil, Quad, eV Power (1 J/s= 1 W) 1 kW = 1,000 W; 1 MW=10 6 W; 1 GW=10 9 W Also expressed as horsepower, BTU/hr Energy and Environment by Toossi

4. Units Convention Dr. Newton, Mr. Joule 235 newtons, 500 kilojoules, 10 kilograms 235 N, 500 kJ, 10 kg 1 mg= 0.001 g 1 kg=1000 g 1 Mg=1 metric ton Power of ten notations PrefixSymbol 10 -12 picop 10 -9 nanon 10 -6 micro  10 -3 milim 10 3 kilok 10 6 Mega (million) M 10 9 Giga (billion)G 10 12 Tera (trillion)T 10 15 PetaP 10 18 ExaE Energy and Environment by Toossi

5. Types of Mechanical Energy Hydroelectric Tides Waves Wind Energy and Environment by Toossi

6. The Golden Rule of Mechanics Whatever you lose in power you gain in displacement. Output work can never be as much as input work The main purpose of machines is to reduce the force (effort) required to do a particular job Energy and Environment by Toossi

7. Simple Machines 1.Ramp 2. Wedge3. Screw 4.Lever 5. Wheel6. Pulley Energy and Environment by Toossi

8. First Class Levers Fulcrum is between the force and weight. Pliers Seesaw Scissors Energy and Environment by Toossi

9. Second Class Levers Weight is between the fulcrum and the force. Nutcracker Wheelbarrow Energy and Environment by Toossi

10. Third Class Levers Force is between the fulcrum and weight. Baseball bat Shovel Tongs Energy and Environment by Toossi