The Science of Sound Waves


by:  Michelle Bertke

Sound can be a difficult concept to portray because the sound waves cannot be seen or touched.  Luckily, there are several at home experiments that demonstrate the properties of sound waves.

Water tank to show ‘Sound Waves’

You can use a fish tank half filled with water to give a visual demonstration The Science of Sound Waves - Educational Innovations Blogof ‘sound waves’.  Water is a perfect medium to show the propagation of waves. This demonstrates how sound waves travel though the air.  There are two ways to display this activity.  One way is to simply press your hands onto the top of the water and allow the waves to be made by the pressure of your hand.  This allows students to see how waves travel though a medium.  You can also use this to point out the aspects of a wave such as frequency and amplitude.  Another way to show waves is to place a speaker next to the tank and allow the sound to produce the waves.  This can show that sound is a form of pressure just like your hand. Read the rest of this entry »


The Chemical Spill and the River


Brian Herrinby: Brian Herrin

One of the difficulties of modeling a flowing water system is the size of the system and the quickness of the flow.  This often makes demonstrations hard to visualize as things happen so quickly.  The model I designed uses large transparent plastic cups and clear tubing that connects them to easily demonstrate how a river can become contaminated by a toxic spill or dump and how the toxic material slowly works its way downstream creating devastation along the way.  In time, the river will eventually run clean, but the damage takes much longer to disappear, and some damage may be permanent.

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The Speed of the Bubble Apparatus


Cynthia Houseby: Cindy House

Bubbles in tubes offer many advantages over spheres on ramps for velocity and acceleration experiments:

  • The bubble stays in the tube! There are no escaped marbles to chase down.
  • The bubble moves more slowly than a marble, permitting more accurate determination of elapsed time.
  • Results are highly reproducible.
  • Many data points can be collected in a short period of time.

The Speed of the Bubble Apparatus | Educational Innovations

A Speed of the Bubble Apparatus to hold and protect the tube is easy to construct from scrap and/or inexpensive materials. It enables even very young students to obtain highly reproducible data quickly. It also protects the tubes from being damaged if dropped or bumped.  Plans and suggested materials are included in this blog. The following experiment is one I use with the elementary students in our after school science club. Read the rest of this entry »


Growing Spheres Help Students Absorb Scientific Principles


John Fedors, Educational Innovationsby:  John Fedors

Hydrophilic spheres from Educational Innovations offer a variety of interesting applications and opportunities for scientific inquiry. They come in a variety of sizes: regular, jumbo, & gigantic. For the following examples, I prefer the regular or #710 size. However, whichever size you choose, they will expand to about 300 times their original dehydrated size.

Growing SpheresAs they absorb the water, they become almost invisible, due to having the same refractive index as water. When placed in de-mineralized or distilled water and kept away from sunlight, they will dehydrate to their original size and can be re-used. Dehydration time will depend on air humidity.

Once enlarged, these clear spheres can be used to demonstrate:

* The lens of an eye (such as those of a shark, calf or sheep) that has the ability to magnify the print on a page. A thin slice may be used to mimic a cornea transplant.

* The suspension of small items such as a coin.

* Roots of a germinating seed.

Enlarged growing spheres can also help to observe the relationship of Surface Area (A=4pr2) to Volume (V=4/3pr3) mass in grams. They can be used to graph relationships. Read the rest of this entry »


What is a Radiometer?


Tami O'Connor, Educational Innovationsby: Tami O’Connor – Taken From Litetronics

The radiometer is a light bulb-shaped device containing an object that looks like a weather vane (wings arranged in a circle like spokes of a wheel).  Developed to measure the intensity of radiant energy, or heat, the radiometer will:

  1. Help you understand the principles of energy conversion.
  2. Show how heat and mechanical energy are products of energy conversion.

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