WORK POWER AND MACHINES CH 14 INTRO TO

WORK, POWER, AND MACHINES CH. 14 INTRO TO PHYSICS

WORK AND POWER • Work • Force x distance • In direction of motion • Nm • joules (J) • What is the work done by a weightlifter lifts a 1500 N barbell Over his head to a height of 2. 0 m?

WORK AND POWER • Power • Rate • watt (W) • Horsepower • 1 hp = 746 W • Ex. • P. 415 #2 • Your Power?

WORK AND MACHINES • Machine • Change force • Size, direction, distance acts • Work in always more than work out

MECHANICAL ADVANTAGE AND EFFICIENCY • Mechanical advantage • X increases input force • Actual mechanical advantage • Output/input • Ideal Mechanical Advantage • Input distance/output distance • Example • P. 425

SIMPLE MACHINES • Lever • Fulcrum • IMA • Input arm/output arm • First Class • Fulcrum between input and output forces

SIMPLE MACHINES • Second Class • Output between input and fulcrum • Third Class • Input between output and fulcrum

SIMPLE MACHINES • Wheel and Axle • IMA = radius input/radius output • Inclined Plane • IMA = distance traveled/height raised

SIMPLE MACHINES • Wedge • Screw • threads

SIMPLE MACHINES • Pulleys • • IMA = # rope sections supporting load Fixed Moveable System • Compound Machines