New Reviews of Hands-On Science!

Photo courtesy of Cheerios Underfoot

 

I recently provided three blog readers the opportunity to receive a copy of Hands-On Science: Particles in Motion.  They agreed to review the book and have written some excellent information for you!

Hands-On Science is a K-6 experiment and activity book.  It provides discussion and thought-provoking questions along with practical application.  The experiments can be completed with an entire homeschool, that is to say, a wide range of ages, at differing levels of difficulty simultaneously.  The best part is, you probably already own every item required to complete the experiments!

But I’ll let you read what these ladies have to say about it.

Here are the Reviews!

If you’re looking to grab a copy of this book for 20% off, be sure to head over to the Homeschool Science Press Facebook page, (like us), and find the discount code!  If you are already a Facebook Liker, head to the special offers tab.

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Experiment: Salt Water and Heat Convection

In our series of experiments on the ocean, we’ve learned about Salt and Solubilities, the Density of Sea Water,  and Salt Water and Buoyancy.

Now we take a look at convection within salt water.

When we discuss heat transfer, we think of the three types: conduction, convection, and radiation.

Conduction takes place between two systems in contact with each other.

Convection occurs when heat is transferred by mass motion of molecules within a fluid.

Radiation is a form of heat transfer that occurs through electromagnetic wave propagation.  Usually we think of the rays of the sun as a major example of radiation.

All three types of heat transfer can be present simultaneously.  As you do this experiment on convection, see if you can also identify the other two types of heat transfer.

Materials:

  • food coloring
  • distilled water
  • salt
  • freezer tray for ice cubes
  • two glass jars

Procedure:

  1. Mix up some of the distilled water with a few drops of food coloring.
  2. Freeze this into cubes.
  3. Fill two glass jars 3/4 full with distilled water.
  4. Add some salt to one of the jars and label.
  5. Place a colored cube into each jar of water.  Observe the movement of the colored water as it melts into the warmer water.
  6. Leave the jars undisturbed as you watch.  Can you identify convection currents?  Where is the colored water going?  Is the colored cold water heavier or lighter than the warmer clear water?  Are the jars the same?  (Remember the Salt Water Density experiment..)
  7. Draw your jars, labeling them as to salt or fresh water.
  8. Write a conclusion statement about your finding.  Note: Yes, the presence of food coloring has affected your experiment, but please assume a small effect, and draw your own conclusions about the relative densities of these two solutions.  You can minimize the coloring effect by using a smaller amount of it.

Remember, as with all experiments, if you require your student to do a writeup, be sure to use the scientific method. Even if you do no writeup, as in the case of younger students, be sure to discuss the steps of the scientific method as you go.

Leave a comment and let us know what ocean experiments you have been doing!

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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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