Learning Simple Machines: 4 Tricks to Help Your Children

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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Teaching Children about the Four Kinds of Kinetic Energy

Your child comes home with questions about the different kinds of kinetic energy. So how do you distinguish between the many different types? You can use common examples to help your child understand the kinds of kinetic energy.

Kinetic energy, or the energy of motion, is the ability to do work. If you use a force across a distance, you do work in a scientific sense. If you slide a book across a table, you have used kinetic energy. The many kinds of kinetic energy include mechanical, electrical, radiant, and sound.

Four Kinds of Kinetic Energy #1- Mechanical kinetic energy is the most familiar and common example of kinetic energy. As an object moves, it has kinetic energy. In order to lift an orange over your head it takes a joule of work. Kinetic energy is measured in joules (rhymes with cool) or Newton-meters, with force measured in Newtons and distance measured in meters. A car accelerating at the same rate as a bicycle has more kinetic energy because it has more mass.

Four Kinds of Kinetic Energy #2– Electrical energy that moves through wires is measured in watts. A joule of work done in one second is a watt, which is named for James Watt, the inventor of the steam engine. Trains used to run using steam engines. If you lift a quarter-pound hamburger with cheese vertically, a distance of one meter in one second, you use a watt of power. Take a close look at a light bulb that is not in a lamp. You will see a number followed by “kw”, or kilowatts, on most light bulbs. Electric motors also have kilowatt ratings. A kilowatt is one thousand watts. Electrical power can also be described as the product of current, measured in amperes or amps, and potential, measured in volts.

Four Kinds of Kinetic Energy #3- Solar energy is the heat and light, or radiant energy produced by the sun. The sun does not burn like a fire does. Nuclear fusion creates the sun’s energy. Helium atoms are formed from lighter hydrogen atoms, in the process creating heat, light, and other particles.

Light energy is a form of radiant energy emitted by accelerating electric charges or the electrons of atoms. Light we see, or visible light, is a small portion of electromagnetic waves, which are partly electric and partly magnetic. Light moves through the vacuum of space or through a material as waves. A wave can be described as a back and forth motion or a vibration.

Light can also move as particles, or photons. Frequency measures how many complete vibrations occur in a given time period, usually a second. Hertz is the unit for frequency, named from Heinrick Hertz who demonstrated radio waves, a type of electromagnetic radiation in 1886. Electromagnetic waves range from the longest, radio waves, to the shortest, gamma rays. The lowest frequency of light that we can see is red and the highest is violet. AM radio waves are broadcast in thousands of hertz, or kilohertz. FM radio waves are broadcast in millions of hertz, or megahertz. Radar and microwave ovens operate in the gigahertz, or billions of hertz range. X-rays and even shorter gamma rays are used in chemotherapy. In a vacuum, all electromagnetic waves travel at the speed of light which is 300,000 km/s.

Heat energy is another form of radiant energy. If you have ever seen a shimmering effect above a paved road or parking lot on a hot day, you have seen heat waves. You can feel heat radiating from a candle flame, a fireplace, or a space heater. Most light bulbs heat up while they operate because the tiny wire inside each bulb, called the filament, heats up and glows.

Four Kinds of Kinetic Energy #4- Acoustic, or sound, energy begins with the vibration of an object. A guitar has strings that vibrate to produce sound. A clarinet has a vibrating reed while a trumpet has a vibrating column of air in the mouthpiece. The human voice has vocal chords. These vibrations start waves in the air. However, sound also needs something to move through, or a medium. There is no sound in outer space since there is nothing for it to travel through. Astronauts outside the space shuttle or the International Space Station use radio waves, a form of electromagnetic radiation, to communicate.

You can use common examples to explain the various kinds of kinetic energy to your child. The many forms of kinetic energy include mechanical, electrical, radiant (heat and light), and sound.

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/teaching-children-about-the-four-kinds-of-kinetic-energy/

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Studying the Ocean


The Sea. Even the name has some kind of elemental drawing power.  People have always been impressed by its size and power.  Boats and trading routes have been important to people since early times.    But, how can you study the ocean when you are landlocked?  How can homeschoolers in Ohio study the sea?  Does Galveston hold all the keys to the study of the gulf or can you take a trip to the ocean at home?

In the United States and, perhaps, in other parts of the world, the oceans are under siege.  Life in the sea has always been in jeopardy from natural events, but today we have additional manmade problems.

Some oceanic problems are: the quality of the beaches, the number and amount of fishes available for catching, and the presence and diversity of life in the upper reaches of the seas.

These three problems are suitable for study for homeschoolers because they are concrete, real problems which can be studied from long distance, if necessary.  The first can even become an action project, too, especially since there are so many lakes and water fronts across the United States.  The problems suggested also present complex legal issues which are excellent starting points for discussing our complicated life as Christians living in a republic.

The quality of the beaches may have changed since your grandparents were growing up….

If you have access to a beach you may decide to conduct interviews in an attempt to document any changes the beach may have undergone whether good or bad.

Young people of thirty or less may not be able to remember the state of the beach in the 1950’s, so you will have to interview some older people to add the perspective of years.  Try to get copies of pictures if you can.  By the way, this activity can be done at any beach, oceanic or freshwater.

Changes to look for:

  1. Presence of private homes on the beach itself.
  2. Presence or absence of garbage on the beach.  What types of trash are found?
  3. Beach closed or open to auto traffic
  4. Distance to shore for fishing trawlers changed.
  5. Has the average size of fish changed in the last two decades?
  6. Addition of groins out into the water to help build up the beach.  (Or allowing them to fall into disrepair or removed totally)
  7. Condition of the substrate (sand ) under the water just off shore has changed.  Is it mostly sand or is it silty?
  8. What are the dangers of the beach to children?  Example:  In the 1950’s, children were warned to only go in the water ankle deep while beachcombing alone and to avoid stepping on man-o-wars.  Now, children should not even go alone and when beachcombing they should be wearing shoes because of the new hazards of the beach.

These are examples of changes which may have happened on your beach in the last sixty years or more.  The nice thing about this project is that action can take place after the research is done.  Beaches can be cleansed of rubble.  Groins can be build to add to beaches.  Regulations can be made or merely enforced.  This kind of project can bring lasting good to a community.

The decline of the fishing industry in the United States is proceeding as it has in many other countries….

Since no one owns the fish no one has an interest in regulating their harvest.  The government has taken this job but as we know the government has many conflicting interests.  In this case, the fish which are allowed to be taken are now smaller and they can be taken from places which are sometimes the breeding grounds of the fishes.  Replacement of the populations must take place, or the breeding stock will have been eaten.

The project for homeschoolers is really a research project.  The student should take one type of fish and trace the regulations governing the harvesting of that fish from about 1900.  Your student can make charts showing the size allowances through the years and the number allowed to be caught.  Remember that commercial fisheries have different rules and allowances for the catch.  Determine the breeding habits of the fish and compare that to the methods be which they are caught.  Remember, this project should be for only one type of fish.

The last topic concerns the uppermost reaches of the oceans:

Life in the oceans depends upon the surface.

The light from the sun hits the surface of the water and is either reflected or is admitted.  The light which penetrates the surface goes down to a point where the light can no longer pass.  This area of upper ocean is the euphotic zone.  In this region, plants can grow using the light from the sun to produce food.  The phytoplankton and zooplankton and the organisms which live off of them all depend upon the transmission of light.  Anything which will block off this light is a hazard to the organisms.  In addition, the dangerous frequencies of light called ultraviolet radiation (UV) can harm the organisms of this region.  If the UV radiation were increasing, the life of the upper region, the euphotic zone, would be in jeopardy.

God designed into the Earth’s ecology, a system of checks and balances, but man’s lack of wisdom may have created umbalances which can jeopardize life in the oceans.  Homeschoolers can measure and research these possible changes.

These facts give us lots of possibilities for research!

Even without a nearby ocean, a homeschooler can get sea salts from the pet store and recreate some of the upper levels of the oceans by adding water.

Using a photocell, a student can measure the light passing through the top few feet of the sea, or through any type of pollution, like suds or oil.  The UV passing through water can be measured by shining a UV light down into the tank at a photocell.

I had one student who hatched brine shrimp (from the local pet store), irradiated them with UV, recorded the results, drew conclusions, and won a science fair competition.

We’ll be posting more articles in the coming weeks on projects and experiments you can do in your homeschool to study the ocean.  Stay tuned!  You may wish to subscribe to the RSS feed so you don’t miss anything!

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