Structure and the importance of the levers
The levers are the most common simple machines which they help man to perform heavy tasks easily. They were first described in 260 B.C, The liver is affected by an effort force and a resistance force, and it is a rigid bar (straight or curved) that rotates around a fixed point called the fulcrum.
The liver consists of:
A resistance force is a force that resulted from the weight of the body that we want to move.
An effort force is a force that is exerted by a person to equilibrate the resistance.
The fulcrum is a fixed point, where the bar rotates around.
The lever consists of a resistance force, an effort force and a fulcrum
Examples on levers
Stapler, Manual broom, Crowbar, Seesaw, Scissors, Bottle opener, Nutcracker, Ice or sweet holder and Wheelbarrow.
Importance of levers
The levers increase the force because they save the exerted effort by using the small force to make a great effort as moving a heavy load.
Examples: crowbar, bottle (soda water) opener, Nutcracker & wheelbarrow.
They increase the distance, where some levers allow the exerting force for a small distance to move an object for a longer distance.
Examples: The manual broom, If your hand moves a small distance at the upper part of the manual broom, the lower part will move a longer distance.
- They avoid dangers as they are used to pick up the hot, cold and poisonous materials. Examples: Ice holder and coal holder (coal tongs).
They increase the speed of the objects that we affect on.
Examples: Hockey bat.
They move the force from one place to another.
Examples: The force of your hand on the manual broom moves from one place to another to collect the garbage without bending.
They have accuracy in performance as they are used to pick up a very small object.
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