Simple Machines
Compound Machine are used the most because
Most machines we use in daily life are made of one or more simple machines.
Compound Machine Examples
Ax, scissor, pencil sharpener ...
Screw Examples
C-clamp, faucet, drill bit, vice, jar lid, corkscrew ...
Forces that naturally exist on the earth
Gravity and Friction
Pulley
Has one or more grooved wheels connected by a rope.
Number of moving parts in a machine
Machines may have few, many or no moving parts.
An Ax is a Compound Machine because
The handle is a lever and the blade is a wedge.
Wheel and Axle
When a wheel is turned, the axle also turns.
Types of Simple Machines
1. Lever 2. Wheel and Axle 3. Pulley 4. Inclined Plane 5. Screw 6. Wedge
Facts about Pulleys
1. A pulley makes it easy to move objects up, down, and across a long distance. 2. The more pulleys you combine, the less force you need to move an object.
Facts about a Lever
1. All levers have a turning point known as a fulcrum. 2. A place where an object is moved. 3. An area where the force is applied.
Facts about Work
1. Some jobs takes more work than others do. 2. More work is required when a greater force is needed. 3. More work is needed when the distance moved is greater.
Facts about Friction
1. Two object rubbing against each other cause friction. 2. Friction causes heat. 3. Friction can be both useful and harmful.
Axle
A bar attached to the center of the wheel.
Wedge Examples
Doorstop, teeth, needle, thumbtack, nail, pin, chisel, plow, saw blade, knife blade, blade of scissors, ax head ...
Pulley Examples
Elevator, water well, blind, flagpole, clothesline, ski lift ...
Wedge Uses
For separating things by cutting, piercing or splitting.
Lever
Is a bar used for raising or moving a weight.
Inclined Plane
Is a flat surface that has one end raised higher than the other end.
Friction
Is a force that makes moving objects slow down or stop.
Compound Machine
Is a machine made up of two or more simple machines.
Simple Machine
Is a machine that has few or no moving parts.
Force
Is a push or a pull.
Gear
Is a special wheels with teeth.
Wedge
Is a type of inclined plane that is wide at one end and tapers to a point at the other end.
Machine
Is an object that makes work easier.
Work
Is produced when a force is used to move an object over a distance.
Energy
Is the ability to do work.
Gravity
Is the earth's force that pulls objects towards the center of the earth.
Effort
Is the force used on a machine.
Load
Is the object being lifted.
Fulcrum
Is the point on which a lever is held up or the point on which the lever rests.
Thread
Is the spiral ridge of a screw.
A Pencil Sharpener is a Compound Machine because
It has a handle which is a wheel that turns on an axle. The handle turns two screws with sharp wedge-shaped that act like blades to sharpen the pencil.
A Scissor is a Compound Machine because
It has two levers with blades that are wedges.
Screw
It is a specialized inclined plane wrapped around a central pole.
Screw Uses
It is used to raise and lower things and also to hold things together.
Inclined Plane Uses
It makes work of moving things up and down easier.
Wheel and Axle Examples
Pizza wheel, fishing wheel, doorknob, cars, roller skates, wagons, pencil sharpener, automobile ...
Inclined Plane Examples
Ramp, escalator, slide, road up a hill, stairway, roof up a house, sloping floor of a theater ...
Lever Examples
See-saw, hammer, your arm, broom, shovel, crowbar, fishing pole, pliers, nail clippers, tongs, baseball bat, paper cutter ...
Two Types of Machines
Simple Machines and Compound Machines
Gears works by
The teeth on the gears turn the other wheels.
How a Lever Works
The weight is placed at one end and a force pushes down the other end.
Pulley Uses
They are used for lifting engines out of a car, on exercise machines to help people strengthen their muscles, by sailors to help raise sails, in a gym to raise or lower the basketball backboard.
Gear Uses
Used inside nearly every machine that turns.
