Simple Machines Nature of Machines Machines are any

Simple Machines

Nature of Machines • Machines are any device that transfer a force from one place to another. – Nutcracker, ramp, engine • All complicated machines contain many small simple machines. – Simple Machines – the basic devices for transferring mechanical forces in all machinery.

Action of Machines 1. Effort Force – the force you apply to the machine. 2. Effort Distance – The distance the effort force acts through. 3. Resistance Force – The force the machine applies to some objects. – Opposite the effort force. 4. Resistance Distance – The distance through which the resistance force acts.

Effort Force Resistance Distance Effort Distance Resistance Force Fulcrum

Laws of Machines • Under ideal conditions, the amount of work put into a machine is equal to the amount of work the machine does. – Ideal conditions refer to NO HEAT, produced by friction, and NO AIR RESISTANCE, created when the machine is used. – Real machines do create friction and therefore creates less energy than it takes in.

Purpose of Machines • Machines make work seem easier and faster. – Multiply a force – Change the direction of a force – Multiply a distance – Multiply speed

Types of Simple Machines • There are six types of simple machines – Compound machines are made from one or more of these six simple machines. 1. Lever – a bar that rotates around a fixed point, fulcrum. Fulcrum

3 Classes of Levers 1. First Class Lever – – Fulcrum is between the input force/Effort and the load. Ex. Claw end of a hammer 2. Second Class Lever – – Load is between the fulcrum and the input force/effort Ex. A can opener 3. Third Class Lever – – Input force/effort is between the fulcrum and the load. Ex. Your arm lifting a weight

Types of Levers • Label the Effort (E), Resistance (R), and Fulcrum (F) in each of the pictures and then determine the type of lever each represents. 1 st Class E 2 nd Class R F E F R 2 nd Class 3 rd Class E E R F

E 2 nd Class R 1 st Class F E R F F E 1 st Class 3 rd Class F R E R

Types of Simple Machines 2. Inclined Plane – A flat surface that slants up at an angle. – Ex. A ramp

Types of Simple Machines 3. Wedge – two inclined planes placed back to back. – The longer and thinner the wedge is, the less energy is required to do work. – Ex. Knife, ax, razor blade.

Types of Simple Machines 4. Screw – an inclined plane that is wrapped around a cylinder – – – Rotates with each turn moving it up or down The closer the threads, or ridges, the easier the work is. Ex. A jar lid, soda bottle cap, bolts

Types of Simple Machines 5. Pulley – A grooved wheel that holds a rope or cable. – – It can change either the direction or the amount of an effort force. 2 Types: 1. 2. Fixed Movable

1. Fixed – attached to a stationary object. 2. Movable – not attached to a stationary object

Types of Simple Machines 6. Wheel and Axle – two circular object of different sizes rotating in a circle. – Two different sized wheels: • Axle – the smaller wheel • Wheel – turns about the smaller axle.

Identify the Simple Machine Lever Pulley Wheel and Axle Wedge Screw Inclined Plane

Identify the Simple Machine Pulley Lever Inclined Plane Wheel and Axle Wedge Wheel and Axle Lever Screw