-Levers-
What is a lever ?
It is perfect for lifting or moving heavy things.
Examples of levers :the seesaw, crowbar, fishing-line, oars, wheelbarrows and the garden shovel.
A lever is simply a plank or ridged beam that is free to rotate on a pivot. .
Parts of a lever
Levers have four very important parts — the bar or beam, the fulcrum (the pivot or the turning point), effort (or force) and the load.
The beam is simply a long plank. It may be wood, metal or any durable material.
The Three Lever Classes
Class 2 lever
Class 3 lever
Class 1 lever
The Fulcrum is between the Effort and the Load.
Exemple:crowbar.
The Load is between the Effort and the Fulcrum. Exemple:wheelbarrows
The Effort is between the Load and the Fulcrum.
Exemple: garden shovel.
Class 1 lever
Class 2 lever
Class 3 lever
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Simple machines are mechanical devices that are used to make work easier. Combinations of two or more simple machines working together are called compound machines. These machines create systems for different kinds of movement to occur when force is applied to a load. Both simple and compound machines make work easier by changing the size or direction of the force. There are six standard types of simple machines. They are the:
wheel and axle
inclined plane
pulley
wedge
Lever
screw
What is mechanical advantage?
Mechanical advantage refers to how much a simple machine multiplies an applied force.
inclined plane is a simple machine with no moving parts.
A wedge is simply a triangular tool, often made of metal, wood, stone or plastic.
A screw is simply an inclined plane around a cylinder.
This simple machine involves two circular objects — a larger disc and a smaller cylinder, both joined at the centre.
A pulley is simply a wheel with a groove in it, and a rope in the groove.
A lever is simply a plank or ridged beam that is free to rotate on a pivot.
Complex Machines
Simple machines are different from complex (or compound machines). Complex machines, like trucks or wagons, or bicycles use many moving parts. They combine many simple machines such as levers, pulleys, and gears to get work done.