Science 8: Mechanical Systems MS1 & MS2

## MS1: Describe various simple machines and use mathematical formulas to calculate

Simple machines use mathematical formulas to calculate:

* Work (Force x distance)
* Force (work / distance)
* Mechanical Advantage (Force output / Force input)
* Efficiency (work output / work input x 100)
* Speed Ratio (#teeth driver / #teeth follower)
* Pressure (Force/area)

### MS1.1: Calculate Work

**Force**: is a push or pull, has magnitude and direction, is measured in Newtons (N)

**Work**: is the transfer of energy through motion, requires a force and distance, is measured in joules (J)

### MS1.2: Simple Machines

A machine is a device used for multiplying forces or changing the direction of a force. Machines can increase the speed with which work is done.

Types of Simple Machines:

* Levers
* A simple machine that changes the amount of force you must exert in order to move an object
* 3 parts of a lever:
* Fulcrum: the pivot point of a lever
* Load: the mass of the object being moved
* Effort Force: the force used to operate a lever
* FLE (fulcrum, load, effort), 123
* **Class 1 Lever**
* Fulcrum is between the effort force and the load
* Teetor totter, scissors, etc.
* **Class 2 Lever**
* Load is between the fulcrum and the effort force
* Nutcracker, wheelbarrow, etc.
* **Class 3 Lever**
* Effort force is between the fulcrum and the load
* Baseball bat, golf club, etc.


* Inclined Plane
* A simple machine that is a ramp or a slope
* Always Force advantages because the effort force is decreased by increasing distance
* Wedge
* A simple machine that is a triangular tool
* Portable inclinced plane
* Used to seperate two objects or pieces, hold objects in place, and/or lift
* Pulley
* A simple machine that has a grooved wheel that carries a rope
* Used to change the direction of the effort force and/or to lift objects with less effort (FA)
* Wheel and Axle
* A simple machine with two wheels of different diameters that turn together
* Can produce distance or Force advantage
* Effort on wheel = Force advantage
* Effort on axle = S/d advantage
* Screw
* A simple machine that is a cylinder wrapped with an inclined plane
* Force advantage
* It turns rotational motion into linear motion

### MS1.3: Mechanical Advantage of Simple Machines

Mechanical advantage is a value that indicates how much a machine multiples force or distance.

* MA>1 Force advantage (Less force needed)
* Trade off is speed or distance
* MA