# Mechanisms-Key terminology

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What is a fulcrum?
The point against which a lever is placed on which it turns or is supported
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What is a lever?
A lever is a rigid beam that can rotate about a fixed point called the fulcrum
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Why are levers useful?
they can act as force multipliers and allow a larger force to act on the load than possible with just a human body, so it is easier to move large or heavy objects
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How can levers be made to amplify force even more
The longer the lever, and the further the effort acts from the pivot, the greater the force on the load will be
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What is mechanical advantage and how do you calculate it?
Mechanical advantage is a measure of the force amplification achieved by using a tool

the ratio of the input force to the output force
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How to remember the class of lever
FLE123
if the fulcrum is in the centre = 1
if the load is in the centre = 2
if the effort is in the centre = 3
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What is a gear or cog?
Gears (cogs') are wheel which is made up of evenly sized and spaced teeth. The teeth of one gear mesh with those of another gear and transmit rotary motion between the two gears

A gear will always rotate in an opposite direction to the gear it meshes wit
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How can gears work with one another?
If both gears have the same number of teeth, they will rotate at the same speed, however if they are different sized then the smaller gear will rotate more quickly - i.e. the Velocity Ratio (or ‘Gear Ratio’)
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What is a driver gear?
A gear that is receving energy/being spun around by another force
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What is a driven gear
It is gaining its motion from the driver gear
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How do you calculate the gear ration
Number of Teeth of the Driver Gear divided by the Number of Teeth of the Driven Gear
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What is an idler gear?
In idler gear is used between two opposing gears that must rotate in the same direction
example if two gears need to rotate clock wise an idler gear will be placed in the middle rotating anticlockwise so the other two match)
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What is a gear train?
A system of gears which transmits motion from one shaft to another
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What is a linkage? And what are they used for?
A linkage is a mechanism made by connecting together rigid links or levers, they manage forces and movement
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the Mechanical Advantage of a linkage is calculated by dividing the force generated at the output (load) by the input force (effort)
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How to calculate velocity ratio in linkages
The Velocity Ratio is given by dividing the distance moved at the input by the distance moved at the output of the linkage
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## Other cards in this set

### Card 2

#### Front

A lever is a rigid beam that can rotate about a fixed point called the fulcrum

What is a lever?

### Card 3

#### Front

they can act as force multipliers and allow a larger force to act on the load than possible with just a human body, so it is easier to move large or heavy objects

#### Back ### Card 4

#### Front

The longer the lever, and the further the effort acts from the pivot, the greater the force on the load will be

#### Back ### Card 5

#### Front

Mechanical advantage is a measure of the force amplification achieved by using a tool

the ratio of the input force to the output force

#### Back 