Simple and complex machines

Simple and complex machines

1. Simple and Complex Machines

2. Agenda Simple Machine Lever Screw Wheel- and- Axle I nclined plane Pulley Wedge Application of simple machines in a complex machine

3. What are Simple Machines? machines with few or no moving parts. make work easier. use energy to work. change the direction of a force such a push or pull.

4. Types of Simple Machines There are 6 simple machines. They are: Lever Screw Wheel- and- Axle Inclined Plane Pulley Wedge

5. Lever A lever is a straight rod that rotates around the fulcrum. There are 3 classes of levers representing variations in the relative locations of the fulcrum, the load and the effort. Class-1 Here fulcrum is located between the effort & the load. Examples of class-1 lever: Pliers, See-saw

6. Class-2 Here Load is located between the effort and the fulcrum. An example of class-2 lever :Wheelbarrow

7. Class-3 Here Effort is located between the Load & the Fulcrum. Examples of Class-3 lever: Human Arm lifting a Load, Tweezers

8. Screw A  screw  is a thin rod with edges ,or threads that curve around it. Turning a screw produces a force that can push the screw into wood or tighten it against a nut. They are also used on jars and other containers so that lids close tightly. Types of screw Lag bolt: A lag bolt is actually a screw that is very large and only partly threaded. The head is square and needs to be turned with a wrench rather than a screwdriver. The lag bolt is used when a standard wood screw simply isn't strong enough. It will probably be the largest screw you'll find in your local hardware store .

9. Wood Screws : The standard wood screw is used to secure one piece of wood to another. Screws with a rounded head are generally preferred for thinner pieces of wood. Screws with a flat or oval-shaped head are a better choice when you will be counter sinking the screw for a more decorative appearance. Brass Screws: Brass screws are essentially just wood screws that are made from brass instead of steel. They are preferable in some cases because they don't rust. Brass screws also add an aesthetic appeal that may be lost when using steel screws.

10. Security Screw : Security screws feature specially shaped heads that allow them to be inserted with a flat-blade screw driver. This special shape features a slot designed in such a way that the screwdriver can grip it only when turning the screw clockwise. The security part of this screw is in the fact that since the screwdriver cannot grip it for turning counter clockwise, the screw cannot be removed.

11. Wheel- and- Axle Wheel and axle work together to make a simple machine. It is a wheel that turns around a rod, called an axle that is fixed to the center of a wheel. A wheel and axle can help move things faster or more easily, and also help things turn. Heavy things can be difficult to push across a surface and can require a lot of force. But, if you add wheels to the bottom, it becomes much easier. When the axle is turned, the wheel moves a greater distance than the axle, but less force is needed to move it. Examples: A steering wheel in a car, Ferris wheels, doorknob, skateboard.

12. Inclined Plane An inclined plane is a flat surface that is raised at one end. It takes less force to move an object up along an inclined plane than it does to lift it straight up. Examples : Ramps, sloping roads

13. Pulley A pulley is a simple machine that has a rope or cable that goes over an wheel. A pulley helps people lift things up with much smaller forces. By pulling down on one end of the rope, a person can lift an object attached to the other end. The length of the string used to lift the pulley determines how much force is needed. Examples : Flag poles, crane, blinds , elevator, fishing rod

14. Types of pulleys Fixed:   A fixed pulley is fastened to one spot, and does not move around. It provides no gain in force, distance or speed, but it changes the direction of the force which means the force is equal on both sides of the pulley and there is no multiplication of force. Examples of fixed pulleys can be seen on flag poles, drapes, or on a sail mast. Movable:   A movable pulley moves along a rope or wire. It provides a gain in force. A movable pulley is used to multiply forces. If one end of the rope is anchored, pulling on the other end of the rope will apply a doubled force to the object attached to the pulley. Compound: A compound pulley, also called a block and tackle, is a combination of a fixed and a movable pulley that means several pulleys are mounted on each axle. This type of pulley changes direction, and yields a gain in force at the same time.

15. Wedge A wedge is a piece of material that narrows to a thin edge. Wedges are used to split things. The purpose or advantage of the wedge is to change the direction of the applied force. Pushing the wedge in one direction creates a force in sideways direction. Example : Axe, knife , chisel, doorstop, saw, hammer, bulldozer, zipper, scissors, fork, bow of a boat or ship

16. Complex machines Simple machines can be combined to create complex machines. Complex machines can be as small as a mechanical watch or as large as a construction crane. Complex machines are also called compound machines. Two or more simple machines work together to form a complex machine. Compound machines can do more difficult jobs than simple machines alone. Examples of complex machines are: Bicycle, wheel barrow, garden hoe , stapler, car jack ,crane , tow truck, bicycle, can opener, lawn mower

17. Simple machines used in complex machines : Compound Machine Simple Machine Wheel barrow Wheel an d axle Lever Garden h oe / Stapler Wedge Lever Car Jack Wedge Screw Crane / Tow truck Lever Pulley

18. Compound Machine Simple Machine Bicycle Wheel and axle Pulley Lever Screw Can opener Wheel an d axle Wedge Lever Lawn Mower Wheel an d axle Screw Lever Wedge

19. A wheelbarrow ’s long handles act as levers, and it rolls on a wheel which acts as wheel and axle. A Garden hoe is made up of a lever and a wedge. The handle of the hoe is a lever, while the blade that cuts into the ground is a wedge. A Stapler is made up of two Simple Machines, Wedge and Lever. The staples in a stapler are wedges because they pierce through papers. The top arm of the stapler is a Lever, it has a fulcrum or a pivot point, which allows the top of the stapler to move up and down. When you put energy on this lever, it transfers energy into a staple, which staples the paper. A Bicycle is a compound machine. Screws are used to hold the pieces together and the seat adjustment is a screw. The wheels and pedals each form a separate wheel and axle system. The pedals are attached to a lever that turns a pulley. The brakes and brake handles are levers. Can Opener is made up of 3 simple machines. First is the wheel and axle which is the handle, when you turn the handle energy transfers to the wedge which opens the can. Second is the wedge, the thing that slices open the can is the wedge. Lastly is the lever, the arms of the can opener are the levers. These two levers open and close on one fulcrum to grip and help open the can.

20. References & Acknowledgements www.goggle.com www.wikipedia.com www.school.enboline.com

21. Prepared By: Thomas

22. Thank you