Simple Machine:
A machine with few or no moving parts. Simple machines make work easier.
Examples: Screw, Wheel and Axle, Wedge, Pulley, Inclined Plane, LeverGears:
Gears are toothed or pegged wheels meshed together to transmit motion and force. In any pair of gears the larger one will rotate more slowly than the smaller one, but will rotate with greater force. Each gear in a series reverses the direction of rotation of the previous gear.
Examples: Clock, Automobile, Drill
Inclined plane:
The inclined plane is the simplest of simple machines because to make it work, nothing moves. You move! An example is a ramp which works by helping you lift things more easily up to a higher level. It can be really hard to carry something up a ladder. But carrying that same box up a staircase is an easier job, and carrying it up a smooth ramp is even easier.
Examples: Staircase, Ramp, Bottom of a Bath Tub
Lever:
A straight rod or board that pivots on a point known as a fulcrum. The fulcrum can be moved depending on the weight of the object to be lifted or the force you wish to exert. Pushing down on one end of a lever results in the upward motion of the opposite end of the fulcrum."In its simplest form, a lever is a stick that is free to pivot or move back and forth at a certain point. Levers are probably the most common simple machine because just about anything that has a handle on it has a lever attached. The point on which the lever moves is called the fulcrum. By changing the position of the fulcrum, you can gain extra power with less effort. A good example of a lever is a see-saw. Let's say that you're really light, and you want to lift a really heavy person on the opposite side. If you put the fulcrum in the middle, you won't have a chance. But if you slide the fulcrum closer to the heavy person, it will be easier to lift. Where's the trade-off? Well, to get this helping hand, your side of the see-saw is much longer (and higher off the ground), so you have to move it a much greater distance to get the lift" -Scholastic
Examples: Door on Hinges, Seesaw, Hammer, Bottle Opener
1st Class Lever
2nd Class Lever
3rd Class Lever
Pulley:
A wheel that usually has a groove around the outside edge. This groove is for a rope or belt to move around the pulley. Pulling down on the rope can lift an object attached to the rope. Work is made easier because pulling down on the rope is made easier due to gravity."The pulley is really a wheel and axle with a rope or chain attached. A pulley makes work seem easier because it changes the direction of motion to work with gravity. Let's say you have to lift a heavy load, like a bale of hay, up to the second floor of a barn. You could tie a rope to the bale of hay, stand on the second floor, and pull it straight up. Or you could put a pulley at the second floor, stand at the first floor, and lift the bale of hay by pulling straight down. It would be the exact amount of work in either case, but the action of pulling down feels easier because you're working with the force of gravity." -Scholastic
Examples: Flag Pole, Crane, Mini-Blinds
Fixed Pulley
Movable Pulley
Combined Pulley
Screw:
An inclined plane wrapped around a shaft or cylinder. This inclined plane allows the screw to move itself or to move an object or material surrounding it when rotated.
Examples: Bolt, Spiral Staircase
Wedge:
A wedge is really an inclined plane turned on its side. But instead of helping you move things to a higher level, a wedge helps you push things apart.
Examples: Axe, Zipper, Knife
Wheel and Axle:
A wheel and axle has a larger wheel (or wheels) connected by a smaller cylinder (axle) and is fastened to the wheel so that they turn together. When the axle is turned, the wheel moves a greater distance than the axle, but less force is needed to move it. The axle moves a shorter distance, but it takes greater force to move it.
Example: Door Knob, Wagon, Toy Car
