Physics 2-6-08

Simple Machines

The mousetrap Game

Wednesday

Big ideas:

A) Determine how do simple machines give an advantage to their user

B) Identify the type, class, effort force and resistance force of a machine used

Types of advantage from a simple machine

• Change in direction

• More force out of machine than what is put in

• More displacement related to force

Types of simple machines

Inclined plane family

Inclined planes

Wedges

Screw

Objects move along plane

Lever Family

Pulley

Wheel and axle

Levers

Rotation about a pivot

All machines are related to an effort and resistance force

• Effort force =

• Resistance force =

Where effort and resistance force are in each type of machine

• Page from your book

Real life examples

• Inclined plane

• Wheel and axle

• Screw

• Wedge

• Pulley

Levers

• All levers have a pivot point (fulcrum)

• Are further divided up into classes

• Classes are based on relative position of Effort force, Resistance force and the fulcrum

1st class lever

• Fulcrum is located anywhere between the forces

• Fulcrum does NOT have to be in the middle of board

• Examples:

2nd class lever

• The resistance force is between fulcrum and effort force

• Examples

3rd class lever

• Effort force is between Resistance force and fulcrum

• Examples

Game Challenge

• The Mousetrap Game

• Composed of a large number of simple machines

• Everyone will create a list of every simple machine used in the operation of a completed game Rube Goldberg Machine

Columns to be filled out

• Step number (#)

• Description of pieces used in step/action

• Description of simple machine (if lever indicate class type)

• Description of Effort force

• Description of Resistance force

• For levers describe fulcrum

Assignment details

• List will be due 2/11/08 (next Monday)

• Be worth at least 25 points

• Based on completion and accuracy

• Typed/ organized in sequence