Simple Machines Flashcards
What is a machine?
A device with which work may be accomplished.
What are the 5 purposes of machines?
- Transform energy
- Transfer energy
- Multiply force
- Multiply speed
- Change direction
Name the 6 simple machines.
- Lever
- Pulley
- Wheel and axle
- Gear
- Inclined plane
- Screw
What is mechanical advantage?
A comparison of the output force to the input force or output distance to the input distance.
True or False: You can gain speed and force simultaneously with machines.
False
What is the fulcrum in a lever?
The pivot point.
In a first class lever, where is the fulcrum located?
Between the effort and the resistance.
Give an example of a first class lever.
Seesaw
What is the relationship between force and distance in a first class lever?
You can gain force or distance but not both at once.
In a second class lever, where is the fulcrum located?
At one end, with the effort applied at the other end.
Give an example of a second class lever.
Wheelbarrow
What is the advantage of a second class lever?
You can only gain force.
In a third class lever, where is the fulcrum located?
At one end, with the resistance at the other and the effort between them.
Give an example of a third class lever.
Retractable landing gear on an aircraft.
What is the primary purpose of a single fixed pulley?
To change the direction of the force.
What is the mechanical advantage of a single movable pulley?
2
What determines the mechanical advantage of a block and tackle?
The number of weight supporting ropes.
What is the mechanical advantage of a block and tackle with four pulleys?
4
What is the relationship between the drive gear and driven gear in a gear system?
The drive gear provides the input force, while the driven gear receives the force.
What is the mechanical advantage when the diameter of the driven gear is smaller than that of the drive gear?
Less force out than force in.
What is the mechanical advantage of a worm gear?
Equal to the number of teeth on the spur gear.
What is an inclined plane?
A simple machine that facilitates raising or lowering heavy objects by applying a small force over a long distance.
Fill in the blank: A bolt operates on the principle of an _______.
Inclined plane
What is the mechanical advantage of a fine threaded bolt compared to a coarse threaded bolt?
Greater mechanical advantage due to more threads per inch.
What does a chisel exemplify in terms of simple machines?
Wedge
How is mechanical advantage calculated for an inclined plane?
Length of incline divided by the height of the incline.
Mechanical Advantage =
Force out / Force in =
Distance out / Distance in
What is the Equation for levers?
fe x de = fl x dl
fe = effort
de = distance from fulcrum
fl = load (weight)
dl = distance from load to fulcrum
Which simple machines operate off the principle of a lever?
lever
pully
wheel and axle
gear
Which simple machine operate off the inclined plane principle?
Inclined plane
screw
