What is work?
Work is only done on an object when a force is applied to that object and the objecf moves over a distance
How is work calculated?
W= f x d
What is work measured in?
Joules, Newton-Meters
What is a machine?
A device that makes work easier
effort force
The force that you put into using a machine
resistance force
The force that the machine experts on the object
effort distance
The distance that you move the distance
resistance distance
The distance that the machine moves
What is work input?
The work that you do in using the machine
How is work input calculated?
Wi=FexDe
What is work output?
The work that the machine does on the object
How is work output calculated?
Wo= FrxDr
What is mechanical advantage?
The benefit of using a machine
Actual Mechanical Advantage (AMA)
A comparison of both forces
How to calculate AMA?
AMA= Fr/Fe
What is ideal mechanical advantage (IMA)
IMA is a comparison of both distances
How to calculate IMA?
IMA= De/Dr
What is efficiency?
Comparison of work input to work output
Is work input greater or less than work output?
Greater
What is the mathematical formula for efficiency?
Work output/Work input x100
What is a perfect machine?
A machine that has no friction, 100% efficient, work input= work output
What does the law of machines state?
No machine is 100% efficient
How can you reduce friction between parts of a machine?
Use lubricants, put on wheels
Pulley
a rope wrapped around a grooved wheel
fixed pulley
a pully which changes the diection of the effort
movable pulley
MĂșltiples The effort force
incline plane
Slanting surface connecting a lower level to higher level
wheel and axle
A lever that rotates in a circle around a rigid pole
Screw
An inclined plane wrapped around a central cylinder
Compound Machine
2 or more machines working together