Simple Machines Helping us lift, lower, fasten, split, cut, divide, and move!
What is a Simple Machine? A simple machine has few or no moving parts. Simple machines make work easier http://www.cosi.org/files/Flash/simpMach/sm1.swf
Simple Machines There are 6 simple machines Wheel and Axles Pulleys Inclined Planes Wedges Screws Levers
Wheels and Axles A wheel and axle is a lever that rotates in a circle around a center point or fulcrum. The axle is a rod that goes through the wheel which allows the wheel to turn Makes it easy to move things by lifting or rolling them, and reducing friction http://www.cosi.org/files/Flash/simpMach/sm1.swf Examples: car, bicycle, office chair, wheel barrow, shopping cart, door handle hand truck, roller skates
Wheels and Axles Gears are a form of a wheel and axle A gear is a wheel with teeth. The teeth fit in between each other and turn. When one gear turns, its teeth push against the teeth of the other gear and they both turn. There are gears on your bike, on a can opener and on an egg beater.
Pulleys Pulleys are wheels and axles with a groove around the outside A pulley needs a rope, chain or belt around the groove to make it do work Makes lifting heavy weights easier by redirecting force Pulleys let you move loads up, down, or sideways. http://www.cosi.org/files/Flash/simpMach/sm1.swf
Types of Pulleys A fixed pulley is a pulley in which the wheel does not move A moveable pulley does not change the direction of the effort force but does increase the size of the force. When you pull on the rope, the pulley and the load come up. A compound pulley, also called a block and tackle, is a combination of a fixed and a movable pulley. This type of pulley changes direction, and yields a gain in force at the same time.
Inclined Planes An inclined plane is a flat surface that is higher on one end Inclined planes make the work of moving things easier Makes it easier to move objects upward; a longer path, but easier lifting http://www.cosi.org/files/Flash/simpMach/sm1.swf A sloping surface, such as a ramp. An inclined plane can be used to alter the effort and distance involved in doing work, such as lifting loads. The trade-off is that an object must be moved a longer distance than if it was lifted straight up, but less force is needed. You can use this machine to move an object to a lower or higher place. Inclined planes make the work of moving things easier. You would need less energy and force to move objects with an inclined plane.
Wedges Two inclined planes joined back to back. Wedges are used to split things. Pushes material apart, cuts http://www.cosi.org/files/Flash/simpMach/sm1.swf
Screws are inclined planes wrapped around a cylinder Screws are inclined planes wrapped around a cylinder. They also act like a wedge albeit with just one edge to separate things. The more gentle the curving, the less force needed but it is needed over a longer distance. If you have tighter curving, you need more force and move less distance as the screw turns. Screws A screw is an inclined plane wrapped around a shaft or cylinder. The inclined plane allows the screw to move itself when rotated. Turns rotation into lengthwise movement http://www.cosi.org/files/Flash/simpMach/sm1.swf
Levers-First Class In a first class lever the fulcrum is in the middle and the load and effort is on either side Helps lift heavy weights using longer distances Think of a see-saw http://www.cosi.org/files/Flash/simpMach/sm1.swf
Levers-Second Class In a second class lever the fulcrum is at the end, with the load in the middle Think of a wheelbarrow
Levers-Third Class In a third class lever the fulcrum is again at the end, but the effort is in the middle Think of a pair of tweezers
Simple Machines Simple Machines can be put together in different ways to make complex machinery
INVESTIGATE! These websites will help you learn more about Simple Machines. After viewing these websites, you will be able to identify different types of each Simple Machine. You will also be able to understand more about each type of Simple Machine. MiKids.com EdHeads.org Dirtmeister’s Simple Machines Simple Machines Complete the chart on the following slide with your partner. Print out 1 copy.
Simple Machine Diagram Describe how it works An unique example