What exactly are simple machines? How do they work? And how do you make learning simple machines easy for your children? Learning simple machines can be accomplished by using common examples to help your child comprehend these basic scientific concepts. Hand tools, silverware, even parts of the human body can all be considered simple physical machines.
Any physical machine makes work easier to accomplish. To a scientist, work is the amount of force (a push or a pull) used along the distance upon which the force acts, or the product of force and distance. For work to be done in a scientific sense, the object must move in the same direction in which the force acts. As you carry a heavy stack of books across the room, you do not do work on the books, since motion and force act in different directions. The motion is in the horizontal direction, along the floor, while the force is straight up, acting against the weight of the books. When you lift the stack of books straight up, you do work on the books, since the applied force and the direction of motion are the same. If you carry the books up or down a flight of stairs, then you do work on the books along the height of the stairs.
Simple, physical machines make work easier by multiplying either the force on the object or the distance involved. A see saw does work on the people sitting on either end. Have you ever changed your position on one end of a see saw to allow a small child sitting on the other end to go up and down? You adjusted one part of a lever to allow it to do work, that is, to lift up the people on each side easier. Learning simple machines is as easy as you and your child experimenting with this concept using a ruler, a pencil, and a few coins. Place the ruler across the pencil at a right angle to the pencil and at the middle of the ruler. Place one coin after another on alternating ends of the ruler and at different distances from the pencil until the ruler balances on the pencil. What do you notice about the types of coins you use? How far away are the coins from the pencil? How many coins do you place on each side of the ruler?
Depending upon your reference, simple machines can be classified into many categories, but the two basic groupings are levers and inclined planes. A lever has two sections, or lever arms, which move around a fixed point called a fulcrum. Levers may include an automobile jack, wheelbarrow, see saw, broom, shovel, or a human’s forearm. An Inclined plane is a ramp or slanted surface along which a force moves an object to different elevations. Two inclined planes placed back to back, form a wedge that is used to split things apart. Inclined planes include staircases, screws, mountain roads, and a human’s front teeth.
Most ordinary hand tools are composed of simple, physical machines. A pen or a pencil is a lever. A door knob that turns is a lever, both for pulling or pushing the door and the door knob itself. A nut cracker is a lever. A wall light switch is a lever. A crowbar is a lever. The length of a nail is a lever, while its pointed tip is an inclined plane. The length of a table knife is a lever and its blade is an inclined plane. A fork is a lever and so is a spoon. The tines on most forks end in points, therefore they are inclined planes. A hand-operated pencil sharpener is a combination of levers and inclined planes. Examine a pair of scissors closely. Can you find these simple machines? The lengths of the blades and handles are levers. The tiny post the levers turn around is a wheel and axel and also a lever. The blades are inclined planes. One edge of each blade is narrower than the other, forming a miniature ramp. By identifying these common items children are learning simple machines without even realizing it.
You can use every day examples to aid your children in learning simple machines. They can help explain what simple machines are and how they function. With practice children can distinguish physical objects as simple machines and determine how they operate. Simple physical machines can be located in the kitchen, in the garage, in the toolbox, and even in the human body.
Lorie Moffat has 20 years of teaching experience in both public school classroom and science museum settings. Contact her about special summer online tutoring packages.
Source: http://www.homeschool-articles.com/learning-simple-machines-4-tricks-to-help-your-children/
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“A machine has value only as it produces more than it consumes” -Martin H. Fischer
First of all thank you for the great ideas on introducing the idea behind simple machines to students. Although I do not home school children I am a high school engineering teacher so your ideas have much to offer. The idea that not only manufactured items but parts of the body are simple machines as well is one that every student should understand. Your scientific explanation of a machine works great and also provides a cross-curricula approach to teaching. To sum it up: you have classified spoons, forks, knives, forearms, crowbars, and hammers as simple machines. It seems to me the focus is placed on the use of inclined planes and levers. Does this mean that anything lacking the above is not a simple machine? Personally I have always viewed simple machines as anything lacking the use of a fuel that needs to be regenerated. My thought has always been that things like a battery that needs recharging or an engine which needs refueling are not simple machines, however components of these items can be. I am currently working on a project in which students design a brake rotor as an extension to a simple machine project. The idea that brake fluid is re-used as force it applied to a brake lever and the caliper compresses on the rotor is one that i feel caters to the simple machine idea.
I have to say that the activity of using a ruler, pencil, and coins to demonstrate the roll of force on a lever is one that I also use in the classroom. I feel that in the event supplies are limited, we need to create activities that are simple, this activity does just that. Thanks for the ideas and advice!
Ken,
Lorrie Moffat wrote a great article, to be sure! I studied engineering in college, so greatly looking forward to being able to teach these things to my children.
And, by the way, I love that you are a high school engineering teacher! We never had that option in my high school! Thanks for doing what you do!
esther