1. Mechanical Energy

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

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

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

5. Types of Mechanical Energy Hydroelectric Tides Waves Wind

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

7. Simple Machines 1.Ramp 2. Wedge3. Screw 4.Lever 5. Wheel6. Pulley

8. First Class Levers Fulcrum is between the force and weight. Pliers Seesaw Scissors

9. Second Class Levers Weight is between the fulcrum and the force. Nutcracker Wheelbarrow

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