Agenda Simple Machine Lever Screw Wheel- and- Axle Inclined plane Pulley Wedge Application of simple machines in a complex machine
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.
Types of Simple MachinesThere are 6 simple machines. They are:1. Lever2. Screw3. Wheel- and- Axle4. Inclined Plane5. Pulley6. Wedge
LeverA lever is a straight rod that rotates around the fulcrum. There are 3classes of levers representing variations in the relative locations of thefulcrum, the load and the effort. Class-1Here fulcrum is located between the effort & the load.Examples of class-1 lever: Pliers, See-saw
Class-2Here Load is located between the effort and the fulcrum.An example of class-2 lever :Wheelbarrow
Class-3Here Effort is located between the Load & the Fulcrum.Examples of Class-3 lever: Human Arm lifting a Load, Tweezers
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 andonly partly threaded. The head is square and needs tobe turned with a wrench rather than a screwdriver.The lag bolt is used when a standard wood screw simplyisnt strong enough. It will probably be the largestscrew youll find in your local hardware store .
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 dont rust. Brass screws also add an aesthetic appeal that may be lost when using steel screws.
Security Screw:Security screws feature specially shaped heads that allow them to beinserted with a flat-blade screw driver. This special shape features aslot designed in such a way that the screwdriver can grip it only whenturning the screw clockwise. The security part of this screw is in thefact that since the screwdriver cannot grip it for turning counterclockwise, the screw cannot be removed.
Wheel- and- AxleWheel and axle work together to make a simple machine. It is a wheel thatturns around a rod, called an axle that is fixed to the center of a wheel. Awheel and axle can help move things faster or more easily, and also helpthings turn. Heavy things can be difficult to push across a surface and canrequire a lot of force. But, if you add wheels to the bottom, it becomesmuch easier. When the axle is turned, the wheel moves a greater distancethan the axle, but less force is needed to move it.Examples: A steering wheel in a car, Ferris wheels, doorknob, skateboard.
Inclined PlaneAn inclined plane is a flat surface that is raised at one end. It takesless force to move an object up along an inclined plane than it does tolift it straight up.Examples : Ramps, sloping roads
PulleyA 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 downon 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 isneeded.Examples : Flag poles, crane, blinds , elevator, fishingrod
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.
WedgeA wedge is a piece of material that narrows to a thin edge. Wedges areused to split things. The purpose or advantage of the wedge is to changethe direction of the applied force. Pushing the wedge in one directioncreates a force in sideways direction.Example : Axe, knife , chisel, doorstop, saw, hammer, bulldozer, zipper,scissors, fork, bow of a boat or ship
Complex machinesSimple machines can be combined to create complex machines.Complex machines can be as small as a mechanical watch or as largeas a construction crane. Complex machines are also called compoundmachines. Two or more simple machines work together to form acomplex machine. Compound machines can do more difficult jobsthan simple machines alone.Examples of complex machines are:Bicycle, wheel barrow, garden hoe , stapler, car jack ,crane , towtruck, bicycle, can opener, lawn mower
Simple machines used in complex machines : Compound Machine Simple Machine Wheel and axle Lever Wheel barrow Wedge Lever Garden hoe / Stapler Wedge Screw Car Jack Lever Pulley Crane / Tow truck
Compound Machine Simple Machine Wheel and axle Pulley Lever Screw Bicycle Wheel and axle Wedge Lever Can opener Wheel and axle Screw Lever Wedge Lawn Mower
A wheelbarrow’s long handles act as levers, and it rolls on a wheelwhich acts as wheel and axle.A Garden hoe is made up of a lever and a wedge. The handle of thehoe 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. Thestaples 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 putenergy on this lever, it transfers energy into a staple, which staplesthe paper.A Bicycle is a compound machine. Screws are used to hold the piecestogether and the seat adjustment is a screw. The wheels and pedalseach form a separate wheel and axle system. The pedals are attachedto 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 andaxle which is the handle, when you turn the handle energy transfers tothe wedge which opens the can. Second is the wedge, the thing thatslices open the can is the wedge. Lastly is the lever, the arms of thecan opener are the levers. These two levers open and close on onefulcrum to grip and help open the can.