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Why are they Useful? Simple machines are useful because they can make a physical job easier by changing the magnitude or the direction of the force exerted to do work.
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WedgeInclined Plane
Screw
Wheel and Axle
Lever
Pulley
Simple machines are useful because they can make a physical job easier by changing the magnitude or the direction of the force exerted to do work.
Have you ever tried to unscrew a nut, bolt, or screw from something with your bare hands and discovered that it was just too tight to loosen even if you had a good grip?
You got the proper tool, such as a screw driveror wrench, and unscrewed it!
Why is it that it's so easy to unscrew with a tool when you can't with your bare hands?
The wrench and screw driver are examples of a wheel and axle, where the screw or bolt is the axle and the handle is the wheel. The tool makes the job easier by changing the amount of the force you exert.
AxleWheel
All of the simple machines can be used for thousands of jobs
from lifting a 500-pound weight to making a boat go. The
reason why these machines are so special is because they make
difficult tasks much easier.
Fulcrum
Lever
Load
Click Here to Learn More
Lever• A board or bar that
rests on a turning point called a fulcrum.
• The object that a lever moves is called a load.
• The closer the object is to the fulcrum, the easier it is to move.
Examples:Hammer, bottle opener,
crow bar
load
fulcrum
lever
Click on the dude to learn more.
Inclined Plane• A flat surface that
is higher on one end
• Used to move an object to a lower or higher place.
• Need less energy and force to move objects.
A screw is an inclined plane wrapped around a post. Click on the light bulb to learn more.
Screw• An inclined plane
that winds around itself
• Has ridges and is not smooth like a nail
• Used to lower and raise things and hold things together.
inclined plane
Examples: jar lid, light bulbs, key rings, spiral staircase
Two inclined planes make a wedge.
Try to catch the saw to learn more.
Wedge• Made up of 2
inclined planes that meet and form a sharp edge.
• This edge can split things apart.
• Used to push 2 objects apart.
2 inclined planes
Examples: knives, axes, forks, nails
Axle
Wheel
Click on the windmill to learn more.
Wheel and Axle• The axle is a rod
that goes through the wheel allowing the wheel to turn.
• Makes movement from place to place easier.
axle
wheel
Examples: cars, roller skates, wagons, door knobs, gears found in watches, clocks , and
bicycles
Wheel
Rope This box is easier to lift because of the pulley. Click on it to learn more.
Pulley• Made up of a rope and
wheel.• Rope fits in the groove
of the wheel. • One part of the rope is
attached to the load.• When you pull on one
side, the wheel turns and the load will move.
• Moves loads up, down, or sideways.
wheel
rope
Examples: flag poles, sailboat, blinds, crane
