simple machines
ways we use them everyday,
6 simple machines!
The six simple machines are lever, wheel and axle, pulley, screw, inclined plane, and wedge.
lever!
Levers are basic machines with three components: the fulcrum, the load and the effort. There are three classes of levers. The longer the distance is between the three components, the easier the load is to lift. The lever is often used to lift loads that are not easy for a person to lift or produce an effort on without a machine. Levers are so common in every day activity that people use them dozens of times a day without noticing.
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. The blades of a knife or a shovel are both wedges. A wedge can also be round, like the tip of a nail, or the tines on your fork. Basically, the wedge works just like a ramp: The narrower the wedge (or the sharper the point of a wedge), the easier it is drive it in and push things apart. But here's the trade-off: To split something apart really wide, you have to push the wedge a long distance.
The Wheel and Axle
A wheel and axle is really two machines in one because you can use each part in different ways. The first way is to roll something along. Wheels help you move an object across the ground because they cut down on the amount of friction between what you're trying to move and the surface you're pulling it against. (The axle is the object that attaches the wheel to the object it's moving.) Since only the very bottom of the wheel touches the ground, there is less surface area to rub — and less friction. Imagine pulling a little red wagon without any wheels! Generally speaking, the bigger the wheel, the easier it is to make something roll.
inclined plane
- The job is much easier if you have a ramp.
- For example, a ramp makes it much easier to push a motorcycle onto a pickup truck.
- A ramp is an example of a simple machine called an inclined plane.
- An inclined plane is a flat, sloped surface.
screw!
The screw is classified as one of six simple machines. It is often described as an inclined plane wrapped around a cylinder. Screws in many forms can be combined with other simple machines such as the lever and pulley to assemble machines as simple as a pair of scissors or as complex as a modern automobile. Machines and devices based on the screw are found everywhere in daily life.
The Pulley
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.