Simple MachinesSimple Machines

Simple machine-Simple machine- a device a device that does work with only one that does work with only one movement.movement.

-Machines make work easier by -Machines make work easier by changing the force you exert in changing the force you exert in size, direction or both.size, direction or both.

-Simple machines try to move -Simple machines try to move something that resists being something that resists being moved. (Ex: friction or gravity)moved. (Ex: friction or gravity)

There are 6 types of simple There are 6 types of simple machines. All are variations machines. All are variations of lever or inclined plane.of lever or inclined plane.

LeverLever Inclined planeInclined plane

1. Lever1. Lever 4. Inclined plane4. Inclined plane

2. Pulley2. Pulley 5. Screw5. Screw

3. Wheel and3. Wheel and 6. Wedge6. Wedge

axleaxle

1.1. Lever- a bar that is free to Lever- a bar that is free to pivot or turn about a fixed pivot or turn about a fixed point.point.

- Fulcrum- fixed point of a lever- Fulcrum- fixed point of a lever- Effort arm- part of the lever Effort arm- part of the lever

where the effort force is where the effort force is appliedapplied

- Resistance arm- part of the Resistance arm- part of the lever where there is resistancelever where there is resistance

There are different types of There are different types of levers.levers.

-1-1stst class Effort class Effort ▲▲ResistResist

Ex: seesawEx: seesaw

scissorsscissors

plierspliers

-2-2ndnd class class Effort Resist ▲ Effort Resist ▲

Ex: Stapler Ex: Stapler

WheelbarrowWheelbarrow

Nail clippersNail clippers

-3-3rdrd class class ResistResist Effort Effort ▲▲

Ex: Ex: TweezersTweezers

Swinging a batSwinging a bat

Fishing rodFishing rod

2. Pulley- a grooved wheel 2. Pulley- a grooved wheel with rope running along the with rope running along the groove.groove.

There are 3 types of pulleysThere are 3 types of pulleys

1.1. Fixed- the pulley is stationaryFixed- the pulley is stationary

2.2. Movable- the pulley can moveMovable- the pulley can move

3.3. Block and tackle- Fixed and Block and tackle- Fixed and movable put togethermovable put together

-Fixed -Movable -Block &

Pulley Pulley Tackle Pulley

3. 3. Wheel and axle- 2 wheels of Wheel and axle- 2 wheels of different sizes that rotate different sizes that rotate together.together.

- Always travel in a circle.Always travel in a circle.

- Effort force is applied to the Effort force is applied to the larger wheel while the smaller larger wheel while the smaller wheel (axle) exerts the wheel (axle) exerts the resistance force.resistance force.

Example of a wheel and axleExample of a wheel and axle

4. 4. Inclined plane- a sloping Inclined plane- a sloping surface used to raise surface used to raise objectsobjects..

Ex: a ramp. Using a ramp, you Ex: a ramp. Using a ramp, you cover more distance but exerts cover more distance but exerts less force.less force.

5.5. Screw- an inclined plane Screw- an inclined plane wrapped in a spiral.wrapped in a spiral.

6.6. Wedge- an inclined plane Wedge- an inclined plane with 1 or 2 sloping sides.with 1 or 2 sloping sides.

-Wedges are moving inclined -Wedges are moving inclined planes.planes.

Ex: Knife or ax blade.Ex: Knife or ax blade.