Machines
what is a machine
A machine is a device that allows you to do work in a way that is easier or more effective
What is the formula to find input work?
Input work = input force * input distance
What is an inclined plane?
Is a flat, sloped surface that allows you to exert your force over a longer distance
What is the mechanical advantage formula for a wedge?
MA wedge =length of wedge / width of wedge
What is an input force?
The force you exert on a machine is called the input force.
What are three ways machines can make work easier?
A machine makes work easier by changing at least one of three factors:
The amount of force that you exert
The distance over which the force is exerted
The direction in which you exert the force
What is the formula to find output work?
Output work = output force * output distance
What is a wedge?
A wedge is a device that is thick at one end and tapers to a thin edge at the other end.
What is the mechanical advantage formula for a screw?
MA screw = length around threads/ length of the screw
What is an output force?
The force the machine exerts on the object is called the output force.
List the 6 types of Simple Machines
Inclined plane
Wedge
Screw
Lever
Wheel and axle
Pulley
What is the formula used to find mechanical advantage?
Mechanical Advantage = output force /input force
What is a screw?
A screw can be thought of as an inclined plane that is wrapped around a cylinder
What is the mechanical advantage formula for a wheel and axle?
MA wheel and axle = radius of wheel / radius of axle
What is efficiency?
The efficiency of a machine compares the output work to the input work. Efficiency is expressed as a percent. The higher the % the more efficient the machine.
What is a compound machine?
A compound machine is a machine that makes use of two or more simple machines.
What is the formula to find the efficiency of a machine?
Efficiency =(output work/input work) X 100
What is a wheel and axle
A wheel and axle is made up of two cylindrical or circular objects fastened together that rotate along a common axis
How do you find the mechanical advantage of a pulley?
MA pulley = # of sections of rope that support the object
What is an ideal machine? Do they exist, why or why not?
An ideal machine is one that would give you 100% efficiency. THEY DO NOT EXIST!!! In all machines some work is wasted due to friction.
What is mechanical advantage?
A machine’s mechanical advantage is the number of times a machine increases the force exerted on it.
What is the mechanical advantage formula for an inclined plane?
MA = length of incline / height on incline
What is a pulley? and What is a lever?
A pulley is made of a grooved wheel with rope or a cable wrapped around it.
A lever is a rigid bar that is free to pivot or rotate around a fixed point
What is the formula for calculating the mechanical advantage of a lever?
MA=distance from fulcrum to input force /distance from fulcrum to output force
What is a fulcrum?
A fixed point that a lever rotates or pivots around