The Energy Ball

December 30, 2009

by:  Sarah Brandt

This uniquely entertaining ball is a fun way to demonstrate open and closed circuits, as well for prompting discussions on conductivity. The following activities are perfect to use in elementary and middle school grades first exploring electricity and circuits.

When both sensors on the ball are touched and a complete circuit is formed, the ball flashes a red light and buzzes.

What makes the energy ball work?

Inside the energy ball is a simple circuit that is completely self-contained. By touching both sensors, the circuit is completed by electrons flowing through your body or another conductive material such as a paper clip. Materials that activate the energy ball are good conductors, meaning they pass electrons easily. Materials that do not activate the energy ball are poor conductors (or insulators), meaning they do not pass electrons easily. Your students will enjoy finding different ways to activate the ball:

One Student: Simply hold the ball so that both sensors are touched or, press one sensor with your hand and the other with a paperclip. Try experimenting with other materials (cardboard, plastic, metal) to see which will activate the ball.

Multiple Students: Using two students, have each student touch a sensor, and then hold hands with one another. See how many students can hold hands and still keep the energy ball buzzing. This is an easy way to demonstrate the difference between open and closed circuits – designate one student to be the “switch.” If the switch releases one or both of the hands they’re holding, the ball will stop flashing, representing an open circuit. Holding hands again will resume flashing, and the circuit will be closed.

An Entire Class: For a fun teaching game, try playing a variation of “Duck, Duck, Goose,” with the energy ball. First, form a circle of hands with the energy ball between two students.  One student should be outside the circle, who will be “it.” This student should then go around the circle, pointing to each person in turn and saying either “closed” or “open.” Once a person has been designated “open,” he or she should break the circuit and try to make it around the circle and complete the circuit before the person who was “it”.

Educational Innovations sells the Energy Ball (SS-30) for $3.95.

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Posted by Tami O'Connor

Energy

December 30, 2009

by: Tami O’Connor

One of the units I enjoyed most as a middle school teacher was the section on energy.  The many awesome hands-on experiments generated such a series of oohs and aahs that it made my already-enjoyable days even more enjoyable!  One of my favorites was a lesson that dealt with the Law of Conservation of Energy.  A consequence of this law is that energy cannot be created, nor can it be destroyed.  (The students would have already explored potential and kinetic energy before the following activity.)

I initiated this lesson reviewing what happens with energy in a closed system.  The students clearly remembered comparing the amount of potential energy to kinetic energy using the example that the height of a roller coaster’s first hill is always greater than the combined heights of the remaining hills.  They were generally able to explain the transfer of energy including heat energy and sound energy in the overall system.

I would then take out a normal playground ball and a meter stick and ask the the students to predict the height the ball would bounce if dropped from a meter off the ground.  Most students accurately predicted that the ball would not bounce as high as the height at which it was initially dropped.  Of course, we would then test our hypothesis.  A few students in each class would always insist that the ball could bounce higher than the height at which it was dropped, so I would invite them to show me how it could happen.  Inevitably, the student would add energy to the system by throwing the ball down to the ground rather than simply dropping it.  This was a great opportunity for discussion and was a topic that we would tap into later in the lesson.

I would then pull out my complete collection of balls that ranged from the hard, less bouncy baseballs to the rubber and highly bouncy super balls and have the students explore on their own.  Though there were noticeable differences in the elasticity of the  balls in my collection, none of them bounced higher than the height at which they were dropped.

My next demonstration utilized a racquetball that I had cut in half… well, actually a little less than half.  I would again ask my students to predict how high the  half-ball would bounce.  The answers varied, but by this time, not one student predicted that it would bounce higher than its drop point.  As before, we tested their hypotheses before moving on to the next step.

Because the racquetball is very flexible, I was able to turn the half-ball inside out thus storing elastic potential energy.  Once again, I asked the students to predict what would happen when I dropped the ball.  Based on their recent experience, they all answered that the half-ball would bounce lower than its drop point.  Of course, because I stored elastic potential energy in this system, once the half-ball hit the ground, it popped right side out and was propelled significantly higher than the point at which it was dropped.  Talk about a discrepant event!

Thank goodness Educational Innovations sells Dropper Poppers.  This product eliminates the time and difficulty of cutting racquetballs in half, not to mention the expense of purchasing racquetballs really intended for use in the court!

Dropper Popper Activities

When this small, “half-ball” is turned inside out and then dropped onto a hard, flat surface, it releases the stored energy and “jumps” higher than the point from which it was released.

EXPLANATION
• Elastic potential energy is energy that is stored as a result of deformation of an elastic object such as a spring or a rubber band.
• Gravitational potential energy is energy that is stored as a result of an object’s position above the ground.

ACTIVITY #1 How High Will a Ball Bounce
Showing your students a regular ball such as a small super ball, basketball, or ping pong ball, survey the class to determine the height at which they predict the ball will bounce if dropped without additional energy. You may be surprised to learn that some students will predict that the ball will bounce higher than the point from which you drop it.

Drop the ball. Students will discover that the ball will never reach the height from which you dropped it. The Law of Conservation of Energy states that energy cannot be created nor destroyed; it can only be transferred as alternate forms of energy. The energy that initially went into the system was transferred out as sound energy and heat energy. The ball will never bounce higher than the initial drop point because the energy that comes out of a system can never exceed the energy that goes in.

Explain to your students that the ball’s energy was stored due to its position above the ground. Because of the force due to gravity, the ball falls down as it is attracted to the earth.

ACTIVITY #2 The Dropper Popper
Show your students the Dropper Popper (POP-100), and ask them to predict the height at which the popper will bounce if you drop it straight down. Drop the popper without turning it inside out and observe the height at which it returns.

Turn the Dropper Popper inside out and explain that by doing work on the popper you are storing energy in it. Have the class predict again the return height of the popper after it is dropped. Drop the popper with the “bulge” pointing upward. When the popper hits the ground the stored elastic energy will be released and will cause the popper to bounce higher than the point from which it was dropped.

ACTIVITY #3 Ping-Pong Ball – Be sure all students wear protective eye wear.
This activity is truly best when each student has his/her own Dropper Popper and a Ping-Pong Ball, (PNG-100). Have the students store energy in the popper by turning it inside out. Then place the ping-pong ball in the “bowl” of the popper. Drop the popper onto a hard surface in such a way that the ping-pong ball remains above the popper and inside of its “groove”.
• Have students estimate how high the ball travels.
• Change the height at which you drop the popper and determine if the height the ping-pong ball travels is based more on gravitational or elastic potential energy.

An additional demonstration of the Law of Conservation of Momentum and Energy can be shown using the AstroBlaster (SS-150).  This device has several balls threaded on a plastic shaft.  When dropped straight downward onto a hard surface, the top ball can rebound to a height equal to five times the original drop!

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Posted by Tami O'Connor

The Amazing Drinking Bird

December 1, 2009

by Tami O’Connor

Invented in 1945 by Miles Sullivan, the “drinking bird” has been a favorite of science teachers in every classroom from kindergarten through college. This amazing device is made of two glass bulbs (one representing the head and the other representing the body) joined by a glass tube (representing the neck).  Between the two bulbs, attached to the glass tube, is a metal fulcrum upon which the bird pivots.  The air has been removed from this closed device, and the bottom ball is filled with a colored liquid that has a high vapor pressure (methylene chloride). The rest of the bird’s body and head is filled with the vapor form of methylene chloride.

The demonstration is set up such that a glass, filled to the top with water, is placed in front of the drinking bird. The glass should be the same height as the pivot point of the bird. The bird’s head should be moistened and then the bird should be given a gentle push to begin it oscillating along the pivot point.  Eventually, the bird appears to drink repeatedly, on its own.  So, how does that happen??

The top bulb (head) of the drinking bird is covered with felt. After the felt is moistened with water and the water begins to evaporate, the temperature in the head decreases. This drop in temperature causes some of the vapor inside the head to condense, causing the pressure inside the birds head to decrease. The decrease in pressure in the top bulb causes the liquid from the bottom to be forced upward from the base. As the liquid flows into the top bulb, the bird’s center of gravity moves upward causing the bird to tip forward, dipping its beak into the glass of water.

After the bird tips over and is horizontal, the bottom portion of the glass tube is no longer in the liquid. The glass tube, now 90 degrees to the surface allows the vapor from the bottom to travel to the top until the pressure is equalized.  At the same time, liquid in the column flows back to the bottom bulb. The weight of the bird is now primarily below the pivot point, so the bird returns to a vertical position.

The liquid in the bottom bulb is now exposed to the temperature of the ambient air, which is slightly higher than that of the bird’s head. This cycle continues as long as there is enough water in the glass to moisten the felt on the bird’s head. This cycle gives the appearance of a bird drinking!

SUGGESTED CLASSROOM ACTIVITIES

I) Classroom Discussion

Q. Is this an example of perpetual motion?

A. No. The cycle repeats itself only as long as the water evaporates from the head

Q. What is needed in order for the Drinking Bird to work?

A. A difference in temperature between the head and body.

II) Student Challenges

  1. Observe the operation of the Drinking Bird and explain how it works.
  2. Discover a way to make the Drinking Bird cycle faster.
  3. Predict what will happen if a fan blows air toward the Drinking Bird. Does it make a difference which direction the air blows?
  4. Predict the result of using warmer or cooler water in the glass.
  5. How long will the bird cycle without needing a refill of the water in the open container? Can you find a way of causing the bird to cycle longer?
  6. Is there a difference in the cycle rate on a humid day vs. a dry day? Can the bird be used to determine the relative humidity in the air?
  7. Predict the result of placing a small inverted aquarium over the bird. Does this cause the bird to cycle more or less? (Note: as soon as the water in this closed system reaches its vapor pressure, water from the felt can no longer evaporate and the bird stops.)
  8. Can you attach a thread to the bird so that it does useful work, e.g. lifting a small paper clip?

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Posted by Tami O'Connor

Chemistry of UV Detecting Beads

November 13, 2009

ronby: Ron Perkins

UV-sensitive beads contain pigments that change color when exposed to ultraviolet light from the sun or certain other UV sources. The electromagnetic radiation needed to affect change is between 360 and 300 nm in wavelength. This includes the high-energy part of UV Type A (400-320 nm) and the low energy part of UV Type B (320-280 nm). Long wave fluorescent type black lights work well; incandescent black lights and UV-C lamps will not change the color of the beads.

The dye molecules consist of two large, planar, conjugated systems that are orthogonal to one another. No resonance occurs between two orthogonal parts of a molecule. Imagine two planes at right angles to one another, connected by a carbon atom. When high energyuv651 UV light excites the central carbon atom, the two smaller planar conjugated parts form one large conjugated planar molecule. Initially neither of the two planar conjugated parts of the molecule is large enough to absorb visible light and the dye remains colorless. When excited with UV radiation, the resulting larger planar conjugated molecule absorbs certain wavelengths of visible light resulting in a color. The longer is the conjugated chain; the longer the wavelength of light absorbed by the molecule. By changing the size of the two conjugated sections of the molecule, different dye colors can be produced. Heat from the surroundings provides the activation energy needed to return the planar form of the molecule back to its lower energy orthogonal colorless structure.

Although UV light is needed to excite the molecule to form the high-energy planar structure, heat from the surroundings provides the activation energy to change the molecule back to its colorless structure. If colored beads are placed in liquid nitrogen, they will not have enough activation energy to return to the colorless form.

The UV detecting beads remain one of the least expensive qualitative UV detectors available today. They cycle back and forth thousands of times.

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Posted by Tami O'Connor

Compressed Air as a Force

July 31, 2009

Normby: Norman Barstow

When the National Research Council produced the National Science Standards in 1995, they did so without including sets of lesson plans nor did they design them as part of a standard curriculum package. They were written to be used as goals for our students’ achievement in science.

In my classroom I always used the National Standards when designing my lessons, and they were always clearly represented in the objectives I set for my students. I have found that the topics of Force and Motion, as well as Air, (as part of a weather unit), can be easily taught using balloons to demonstrate the concepts of each. I have designed two different lesson activities that can be used to meet the following standards.

National Science Standards
Content Standards: K-4
Physical Science; Content Standards

  • An object’s motion can be described by tracing and measuring its position over time.
  • The position and motion of objects can be changed by pulling or pushing. The size of the change is related to the strength of the push or pull.

National Science Standards
Content Standards: 5-8

  • The motion of an object can be described by its position, direction of motion and speed.
  • An object that is not being subjected to a force will continue to move at a constant speed in a straight line.
  • If more than one force acts on an object along a straight line, then the forces will reinforce or cancel one another, depending on the their direction and magnitude. Unbalanced forces will cause changes in the speed or direction of an object’s motion.
  • Energy is transferred in many ways.

Balloon Rockets
In a recent workshop I attended, which presented a module on Air and Weather, ‘Balloon Rockets’ was an activity used to show that compressed air can exert pressure to propel a balloon rocket.

The activity used a straw threaded through fishing line, which was stretched across the room. A ziplock bag was then attached to the straw, and the inflated oblong balloons were launched by placing them into the open bag. The force produced by the balloon propelled the straw along the fishing line.

I noticed that the balloons tended to make the bag move from side to side, thus decreasing the distance traveled. We tried the activity again using balloons directly attached to the straw with masking tape. The oblong balloon traveled much farther than the ziplock bag attempt. Next, I introduced the Educational Innovations Rocket Balloons. BalloonOnALineWhat a difference, both in distance traveled and speed. The Rocket Balloons release the compressed air steadily from the opening of the balloon to the weighted tip thereby pushing the straw farther along the fishing line.

Balloon powered car

Another recent discovery I made in my basement was a compressed air (balloon powered) car that I saved from an NSTA workshop I had once attended. The ‘car’ was built with a piece of cardboard as the frame and an axle system made using a wooden skewer inside a drinking straw. The ‘wheels’ were bottle caps and the ‘engine’ was a straw with a balloon attached.

BalloonPoweredCar

While the oblong and/or round balloons worked fine, I wanted to try the EI Rocket Balloon. I had to modify the ‘car’ to account for the increased length and mass of theBalloonPoweredCar2 rocket balloon. The new chassis was now 4 X 14 inches, and I moved the wheels accordingly for this ‘super sized’ car. Again, the difference increased significantly in both distance and speed.

In addition to meeting the above National Standards, these are perfect experiments for elementary and middle school students on manipulating variables and testing hypotheses using the scientific method.

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Posted by Tami O'Connor

UV Radiation Activity

March 25, 2009

tamiby: Tami O’Connor

The sun is our primary source of ultraviolet radiation, however, there are a number of artificial sources of UV light including black lights, tanning beds and mercury vapor lamps. Ultraviolet radiation is usually considered to be a bad thing for very good reasons.

Generally speaking, there are three types of UV radiation here on Earth; UVA, UVB and UVC. Though the most destructive, UVC is almost never seen in nature because the earth’s atmosphere absorbs all of it. Though less destructive, overexposure to UVB can lead to all kinds of maladies including sunburn, some forms of skin cancer and cataracts.

UVA is the most common type of ultraviolet light found on Earth’s surface. It is responsible for the tanning effects of human skin and has the benefit of providing Vitamin D. However, overexposure to UVA can lead to toughening of the skin, suppression of the immune system and increased incidence of cataracts.

Unfortunately, UV radiation is invisible to the naked eye (unless, of course, you’re a honey bee…), so accidental overexposure to it is not uncommon. It is, however, essential to educate your students to the effects of this radiation as well as how to avoid overexposure.

There are a number of activities you can do in all classrooms from kindergarten through college with a plethora of materials including Ultraviolet Detecting Beads, UV Filters, UV Outside Detectors, UV Atmospheric Light Meters, and the like. One of my favorite activities to do in the upper elementary and middle school classroom is very easy and quite inexpensive. All you need is a piece of newspaper (with text), a plastic snack bag, sunscreen, black construction paper, tape, and a large poster board.

sunblockexperiment

Have each of your students cut a piece of newspaper to fit snugly inside a Ziploc snack bag. On each snack bag draw two lines with a marker dividing the bag into equal thirds from the top of the bag to the bottom. On the left hand third apply a thin coat of sunscreen (varying the SPF between students can yield interesting results). Cover the middle third with black construction paper. The right hand third should be left fully exposed.

Tape all the snack bags to a large piece of poster board such that none overlap any others. Bring the poster board with all the snack bags secured to it into the morning sunlight. Be sure to place the poster board in a place that it will be fully exposed to direct sunlight all day. At the end of the day bring the poster board inside, and the next morning, instruct your students to carefully remove their newsprint from the bags and record their observations.

Of course, there are other great experiments that can be found on our website, and if you have any ideas that we don’t, we would love to hear from you if you are interested in sharing… from your classroom to ours!

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Posted by Tami O'Connor

Film Canisters

February 26, 2009

tamiby: Tami O’Connor

During my 16 years in the classroom, my students and I have accumulated a plethora of fond and one or two not-so-fond memories. One memory that still makes me cringe deals with the amount of time I spent traveling from one film-processing center to the next, in search of those perfect little containers I made such great use of within the walls of my science can150classroom. I’m sure you know exactly what I’m talking about…those little containers, which could be used for everything from conveniently and securely storing small amounts of solids or liquids to acting as the engine compartment of the well-known makeshift paper rocket. What versatile things those film canisters are…

Thanks to Bob Morse of St. Albans, we have found yet another use for those mini containers. In this short segment, Bob demonstrates how to construct a simple Leyden jar that is large enough to produce a nice spark, yet small enough to be perfectly safe, and best of all, durable enough to reuse over and over again! The only materials needed are a film can, a small strip of aluminum foil, a paper clip, a small section of PVC pipe, a cloth or piece of fur to rub on the pipe and a small amount of water.

can3001In this age of digital cameras, 35mm film canisters are becoming a thing of the past. Educational Innovations can supply you with clean film canisters, translucent or opaque, to use in your classroom. Check out the other activities we have for film canisters, and please feel free to share your own ideas with us.

1 Comment | College Level, Energy, Experiments, High School Level, Middle School Level, Physics, Static Electricity | Tagged: , | Permalink
Posted by Tami O'Connor

X-Rays with Tape?

February 26, 2009

tedby: Ted Beyer

Here at Educational Innovations we always keep an eye out for that new science related story or gadget that might turn into a great product for teachers to use in their classroom. More often than not, if we do spot something, it turns up at the lunch table as a topic of conversation. Recently, I heard something on the radio that made me think that it was, perhaps, April 1, 2008 rather than late October. It seems that scientists have discovered that if you pull 3M® brand Scotch Tape off the roll while in a vacuum, it will admit a significant quantity of X-rays. This sure sounded like lunch conversation material, so I did a little research.

It turns out that the actual science behind this behavior is not understoodxry135 well by the scientists themselves. What is clear was reported by the Associated press, “Rapid pulses of X-rays, each about a billionth of a second long, emerged from very close to where the tape was coming off the roll. That’s where electrons jumped from the roll to the sticky underside of the tape that was being pulled away, a journey of about two-thousandths of an inch, Escobar said. When those electrons struck the sticky side they slowed down, and that slowing made them emit X-rays.” The effect was first noted by Russian researchers in the 1950s. What THEY were doing with tape in a vacuum is not clear either!

The power of the X-rays was sufficient for the researchers at UCLA to actually create an image of a human finger using their apparatus and some standard X-ray film. They believe that the effect can be exploited to create low cost, light weight, low power X-ray devices for use in remote areas, or by emergency personnel such as paramedics.

All of this started us wondering – could we use items around the shop to reproduce the effect? After all, we have a vacuum chamber, and lots of tape, as well as neodymium magnets that might be used to move the tape through the chamber wall… Then our hectic show season, our frenzied work on the American Physical Society’s Physics Quest project and what for us is a very busy time filling orders before the holidays all took away any hope of time to work on the project. Perhaps one of you can whip something up that you could share with us.

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Posted by Tami O'Connor

Static Electricity Activities with the FunFlyStick™

October 16, 2008

ronby: Ron Perkins

This static generator amazes adults and children alike, and is the perfect static electricity demonstration for any classroom. Simply touch the FunFlyStick to the Mylar FunFlyers, and watch them instantly expand and float. Inside the Fun Fly Stick is a moving rubber band, which creates a static charge on the wand. When the wand is touched to the Mylar shape, this charge transfers from the Fun Fly Stick to the Mylar. Because like charges repel, the Mylar instantly expands and floats above the Fun Fly Stick wand.

FunFlyStick from Educational Innovations

FunFlyStick from Educational Innovations

This movie requires Adobe Flash for playback.

I. Move an Empty Soda Can Without Physically Touching the Can!

Materials: FunFlyStick™; empty 12 oz. soda can

Procedure:

A. Place an empty soda can on its side on a level surface.

B. Activate the Fun Fly Stick™ and hold the charged wand parallel to the can. As the wand is moved closer to the can, the can will start to roll toward the Fun Fly Stick™. Try to keep the Fun Fly Stick™ separation distance equal and ahead of the movement.

Explanation:

The positively charged FunFlyStick™ induces an opposite charge in the empty soda can closest to the wand. The can becomes attracted to the Fun Fly Stick™.

II. Determine the Type of Charge on the FunFlyStick™!

Materials: FunFlyStick™; piece of PVC Tubing (ca 25 cm x 2.1 cm); piece of wool cloth (ca 10 cm x 10 cm); roll of transparent tape

Procedure:

A. Affix the end of a freshly pulled piece of transparent tape to a table so that most of the tape hangs in the air.

B. Vigorously rub a small length of PVC pipe with a wool cloth and bring the pipe close to the tape without touching it. Notice whether the tape is attracted (exhibiting a positive charge) or repelled (exhibiting a negative charge) by the negatively charged PVC pipe. This allows you to determine the charge on the tape.

C. Activate the Fun Fly Stick™ and, as you approach the tape (without touching it), notice whether the Fun Fly Stick™attracts or repels the tape. Knowing the charge on the suspended tape from step #2, use this information to determine the charge on the FunFlyStick™.

Explanation:

As you pull a piece of sticky tape from its roll, the tape becomes either negatively or positively charged. As you rub a piece of PVC pipe with a cloth, the pipe always becomes negatively charged. Knowing that opposite charges attract and like charges repel, you can then determine the type of charge on the tape and then on the FunFlyStick™.

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Posted by Tami O'Connor