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What is work?

Transfer of energy through motion

2 things that must be present for work to actually occur

1. There must be motion
2. Motion must be in the same direction as the force

Work unit

Joules (J)

Formula for work

Force • Distance = work

Power unit

Watts

Power Formula

Work ÷ time = power

What is a machine?

Something that makes work easier

Simple machines

-Lever
-Pulley
-Wheel and axle
-Inclined plane
-Screw
-Wedge

Simple machine examples

Lever- seesaw, crow bar
Pulley- window blinds, sailboat pulleys
Wheel and axle- ferris wheel, door nob, car tire
Inclined plane- staircase, ramp
Screw- screws, spiral staircase, vice
Wedge- knife, wood stopper

lever definition

a rigid bar that pivots around a fulcrum

pulley definition

a wheel and axle with a grove and a rope and chain connected to it

wheel and axle definition

a wheel that rotates around a shaft (axle)

inclined plane definition

a sloping surface

screw definition

spiral inclined plane around a cylinder

wedge definition

inclined plane with 2 sloping sides

lever MA

MA = effort arm length / resistance arm length

pulley MA

count all the ropes besides the one that is being pulled down

wheel and axle MA formula

wheel radius ÷ axle radius = MA

inclined plane MA formula

length ÷ height = MA

screw MA

closer the threads are the higher the MA

Wedge MA

thinner the blade the higher the MA

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