Simple Machines Flashcards
Simple Machine
A device that allows the user to multiply a force or a distance
First Class Lever
Fulcrum located between the effort and the resistance
Used to gain a mechanical advantage
Second Class Lever
Resistance located between the fulcrum and the effort
Used to gain a mechanical advantage
Third Class Lever
Effort located between the fulcrum and the resistance
Used to gain a distance advantage rather than a mechanical advantage
Lever Equation
Mechanical Advantage = Resistance / Effort = Effort Arm / Resistance Arm
Pulleys
Mechanical Advantage is directly proportional to the number of ropes supporting the load
Used to gain a mechanical advantage
A pulley system usually consists of at least a traveling block and a stationary block with a length of rope strung between them
Single Fixed Pulley
Used to change the direction of the applied force
MA = 1:1
Single Movable Pulley
Effort rope comes off the movable pulley and is considered a support rope
MA = 2:1
Multiple Pulley System
If the effort rope comes off the fixed pulley, it does not add to mechanical advantage
Count the number of ropes that come off the movable pulley
Multiple Pulley
If the effort rope comes off the movable pulley it is considered a support rope, then count it as part of the mechanical advantage
Gears
Used to gain a mechanical advantage, change speed, change direction of rotation, change torque
Idler Gear
The purpose of the idler gear is to allow the drive and driven gear to rotate in the same direction
Incline Plane
Offers a mechanical advantage
Incline Plane Equation
MA = Run (L) / Rise (I) = R / E = L / I
Gear Equation
MA = Driven Teeth / Drive Teeth = Drive RPM / Driven RPM = Driven Torque / Drive Torque
