2. A machine is a device that helps make work easier to perform by accomplishing one or more of the following functions:
transferring a force from one place to another,
changing the direction of a force,
increasing the magnitude of a force, or
increasing the distance or speed of a force.

3. are devices which does work (w = f x d) with only 1 movement.

4. There are 6 different simple machines. 1. Lever
2. Pulley
3. Wheel & Axle
4. Incline Plane
5. Wedge
6. Screw

5. The force then produced by the machine is called the resistance force.
The force put into a machine to do the work is called the effort force. That is what you apply.
The force then produced by the machine is called the resistance force.
So the hand is applying the effort force, and the resulting force which lifts the rock is the resistance force.

6. a machine can actually produce more force than you put into it
a machine can actually produce more force than you put into it. That’s how you might be able to lift a person on the other side of the teeter totter, even though they may be heavier than you.

7. A LEVER is a rigid bar which pivots about a fixed point, called a fulcrum or axis.

9. There are 3 parts to a lever:
1. Axis
2. Effort arm - where the Fe is applied
3. Resistance arm - where the Fr is applied
f Effort Arm
Resistance Arm g

10. There are also 3 different classes of levers
There are also 3 different classes of levers. 1st class, 2nd class, and 3rd class.
The class is determined by how the 3 different parts are arranged in relation to each other.

11. 1st class levers have the fulcrum in the middle.

12. First Class Lever
In a first-class lever the fulcrum is located at some point between the effort and resistance forces.
Common examples of first-class levers include crowbars, scissors, pliers, tin snips and seesaws.
A first-class lever always changes the direction of force (I.e. a downward effort force on the lever results in an upward movement of the resistance force).

14. 2nd class levers have the resistance force in the middle.

15. Second Class Lever
With a second-class lever, the load is located between the fulcrum and the effort force.
Common examples of second-class levers include nut crackers, wheel barrows, doors, and bottle openers.
A second-class lever does not change the direction of force. When the fulcrum is located closer to the load than to the effort force, an increase in force (mechanical advantage) results.

17. 3rd class levers have the effort force in the middle.

18. Third Class Lever
With a third-class lever, the effort force is applied between the fulcrum and the resistance force.
Examples of third-class levers include tweezers, hammers, and shovels.
A third-class lever does not change the direction of force; third-class levers always produce a gain in speed and distance and a corresponding decrease in force.

21. How do we Calculate Mechanical Advantage of a Lever- MA = length of effort arm ÷ length of resistance arm.

22. Wheel and Axle
The wheel and axle is a simple machine consisting of a large wheel rigidly secured to a smaller wheel or shaft, called an axle.
When either the wheel or axle turns, the other part also turns. One full revolution of either part causes one full revolution of the other part.

24. Pulley
A pulley consists of a grooved wheel that turns freely in a frame called a block.
A pulley can be used to simply change the direction of a force or to gain a mechanical advantage.
A pulley is said to be a fixed pulley if it does not rise or fall with the load being moved. A fixed pulley changes the direction of a force.
A moveable pulley rises and falls with the load that is being moved. A single moveable pulley creates a mechanical advantage.
A Compound pulley is two or more pulleys combined and is a combination of both a fixed and a movable.

27. Inclined Plane
An inclined plane is an even sloping surface. The inclined plane makes it easier to move a weight from a lower to higher elevation.

28. Inclined Plane
The mechanical advantage of an inclined plane is equal to the length of the slope divided by the height of the inclined plane.
While the inclined plane produces a mechanical advantage, it does so by increasing the distance through which the force must move.

30. Wedge
The wedge is a modification of the inclined plane. Wedges are used as either separating or holding devices.
A wedge can either be composed of one or two inclined planes. A double wedge can be thought of as two inclined planes joined together with their sloping surfaces outward.

31. Screw The screw is also a modified version of the inclined plane.
While this may be somewhat difficult to visualize, it may help to think of the threads of the screw as a type of circular ramp (or inclined plane).

32. MA of an screw can be calculated by dividing the number of turns per inch.

33. Summary Wedge Wheel and Axle Lever Inclined Plane Screw Pulley
Pushes material apart, cuts
Wheel and Axle
Makes it easy to move things by rolling them, and reducing friction
Lever
Helps lift heavy weights using longer distances
Inclined Plane
Makes it easier to move objects upward; a longer path, but easier lifting
Screw
Turns rotation into lengthwise movement
Pulley
Makes lifting heavy weights easier by redirecting force