Thursday Physical Science

Simple Machines Identification

Calculate your power output

• For the time your walked, how many 60 watt bulbs you have provided the power needed to light?

• How valuable was your effort.1000 watts provided for 1 hour is worth

7-10 cents Value (in cents) =

(power) x (time (in hours)) x 8.5

Main Purpose of Simple Machines

• To make work easier to do

• Change direction of force

• Change the amount of force or distance traveled

Two families of simple machines

Inclined plane family

• Inclined planes

• Screws

• Wedge

All have slanted surfaces and an object or another surface interaction

All have motion of at least one surface/object

The lever family

• Levers

• Pulleys

• Wheel and axle

All involve rotation about a point

Pulleys

Wheel and axle

Levers

• Composed of a:Beam

Pivot (Fulcrum)

Placement of the fulcrum, input force and output force determined the class of lever

1st class lever

Input force Output force

2nd class levers

3rd class levers

Weekend assignment

• Due Monday:

• Find and create a picture of a clearly definable simple machine that is used in the real world

• At least one picture of each type and class of simple machines (8 in all) from the newspaper, magazines, the internet, or from pictures you take, draw or have.

• These pictures have to show the machine in a real life application

• Each example should be clearly labeled and all pivots on the levers marked

Mousetrap game

Real life mousetrap game

Rube Goldberg machines

• A very complicated machine that achieves a very simple purpose