Levers
The number of lever classes
What are first, second and third?
Force times distance
What is the formula for work?
The unit for force
What is a newton?
Examples of simple machines
What are pulleys, inclined planes, and levers?
How do simple machines make work easier?
They increase the distance through which force is applied, change the direction of applied force, or they multiply the force that is applied to an object,
The three parts of a lever
What are the fulcrum, effort, and resistance?
Work divided by time
What is the formula for power?
The unit for work
What are joules?
A simple machine consisting of a flat surface whose opposite ends are at different heights.
What is an inclined plane?
How can a man move a train?
Based on the law of torque, a man can move a train if he is using a lever. If he is a certain distance from the fulcrum, his force will create more torque than the train, causing the lever to lean towards his side and the train to move towards him.
Examples of each type of lever
1st: crowbar 2nd: bottle opener 3rd: tongs
Input distance divided by output distance
What is the formula for ideal mechanical advantage?
The SI unit for power
What are watts?
A simple machine consisting of a wheel with a rod running through its axis acting as the pivot point
What is a wheel and axle?
Is a wheel all by itself a simple machine?
It is not, because it cannot decrease/increase force or change direction on its own.
What are the force positions in a second class lever?
FRE (fulcrum, resistance, effort)
Output force divided by input force
What is the formula for actual mechanical advantage?
The English unit for power
What is horsepower?
These are three examples of wheel and axle machines
What are gears, single pulleys, and block and tackle machines?
How does a screw do work
The inclined plane around the screw, called the thread, increases the force that you apply to it and turns it into upward or downward force.
How does the law of torques apply to first class levers?
The law of torques states that a system's torque is equal to an object's force on the system times its distance from the center of the system.
This law explains how a bigger object closer to the fulcrum has the same amount of torque as a smaller object farther away from the fulcrum
(Wout/Win)x100 OR (AMA/IMA)x100
What is the formula for efficiency?
How efficiency is expressed
What is a percentage?
This is how you determine how much easier machines make your work
What is the actual mechanical advantage and efficiency?
How can your arm be described as a lever when you pick up a glass of water? What class of lever is it?
Your elbow acts as the fulcrum, your forearm acts as the effort, and the glass of water acts as the resistance, making it a class three lever.