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Fabulous Physics Demos, Toys and Then Some. http: //www. youtube. com/watch? v=LZ 5 Hp. HWl. DS 8 http: //www. youtube. com/watch? v=pat 0 gl. CIblo

Falling Bodies. • Ask the students to time the fall of a dropped cup cake liner. • Have them time 2 dropped at once. And then 3. • Ask them how speed is related to the number of liners dropped. https: //www. lhup. edu/~dsimanek/scenario/ demos. htm

ARISTOTELIAN FALLING BODIES. At terminal speed the drag force on the body is equal in size to the force due to gravity, Fdrag = mg. If the drag is proportional to some power of the speed, say the second power, Fdrag = kv 2, and the body reaches terminal speed quickly, then the distance of fall will be approximately d = vt. Let's find the ratio of distances two objects of different mass will fall. So, d 2/d 1 = (F 2/F 1)1/2 = (m 2/m 1)1/2. Then if the mass ratio is 4, the distance ratio is 2. If the mass ratio is 2, the distance ratio is 1. 414. These may be tested by holding the two objects at heights in these ratios and releasing them simultaneously. They will plop on the floor simultaneously, much to the surprise of students. https: //www. lhup. edu/~dsimanek/scenario/ demos. htm

BALL IN FUNNEL Blow into the small end of a funnel containing a ping pong ball. The ball will not fall out even though the funnel is inverted, so long as air is moving between the ball and the funnel wall. What is going on here? Stores that sold vacuum cleaners used to attract customer's attention by setting up this demo with a vacuum cleaner blowing air through a funnel, and a lightweight colorful ball bouncing above the funnel, suspended there. Would this also work if the vacuum cleaner were reversed, to "suck" air through the funnel? Are you sure that isn't the way they were doing it? https: //web 2. ph. utexas. ed u/~phy-demo/demotxt/2 c 20 -35. html

INVISIBLE THWACK. A setup of two large nails in a board, the rubber band being stretched over them, and a card of any sort set upright a short distance (about 1 cm) beyond one of the nails. First snap the band without the card in place. Ask students to describe the motion of the band in detail. They usually will not suggest that the front of the band ever breaks contact with the nail. Raise the issue. Then do the card demo to confirm your hypothesis. https: //www. lhup. edu/~dsimanek/scenario/ demos. htm

Some may still doubt that the band hit the card, thinking perhaps that you jiggled the table or the board, or even blew on the card to knock it over. If they don't suggest this, suggest it yourself. "How can we test the hypothesis that the band knocked the card over, when our eyes can't see it do that? " Substitute a sense which isn't as easily fooled as the eye. Have a student put a finger where the card was, to feel the band hit the finger. https: //www. lhup. edu/~dsimanek/scenario/ demos. htm

One answer is commonly seen and seems superficially plausible: When the band is stretched, the front nail (B) exerts a force on it, but your hand balances that force. When you release the band, there's an unbalanced force of the front nail (B) forward on the front end of the band. This gives a forward impulse. The momentum of the band is forward, and its center of mass moves forward faster than the band can relax to its unstretched position. It takes some time for the front end of the band to "know" that the other end has been released. That is, it takes some time for any physical effect of the release to reach the front end. https: //www. lhup. edu/~dsimanek/scenario/ demos. htm

Does the forward motion from nail (B) begin only after the band is fully relaxed or the moving end hits the nail (A), or the compressional wave from end (A) has reached (B)? What if nail (A) weren't there? https: //www. lhup. edu/~dsimanek/scenario/ demos. htm

Holding a Ball in Midair. Turn a hair dryer on and hold a ping pong ball in the air with it. Bernoulli's principle can be shown by balancing an inflated balloon or beach ball on a jet of air from the output end of a vacuum cleaner. The balloon will hover near the ceiling and will not fall off even when the air jet is tipped at a considerable angle. A ping pong ball balanced on a fine jet of water illustrates the same principle. You can even lie on your back on the floor and blow upward to support a ping-pong ball. Or blow through a vertical tube. Or stand up and blow through a tube bent in a right angle, with the open end up. https: //www. lhup. edu/~dsimanek/scenario/demos. htm

Suspended weight with string above and below. Which string will break when you pull the lower string? Slowly pull on the lower string or quickly jerk the string depending on what the class thinks. https: //www. lhup. edu/~dsimanek/s cenario/demos. ht m When the lower string is pulled slowly, the top string breaks. When the lower string is jerked the lower string breaks. The reason for the time delay is that in F=ma applied to that mass, m is large, so a is small. To really understand this demonstration one must remember that a string doesn't break until it is stretched (elongated) to its breaking point.

FND THE CENTER OF GRAVITY OF A METER STICK With your hands stretched out rest a horizontal stick on the index fingers of each hand. Slowly move your hands together until the palms meet. Regardless of the starting position of your hands, the center of gravity of the stick will be at the point where your hands come together. What allows this to happen? A meter stick is good for this demo. One can even tape a weight at some point on the stick and it still works. A two-dimensional version: Use a large dinner plate, with objects on it, perhaps even a glass of water. Use three fingers spread wide to support it. Bring the https: //www. lhup. edu/ ~dsimanek/scenario/d emos. htm

Fan and string 1. 2. 3. 4. Take a portable fan and tie a string on the bottom of the battery holder. Add a weight to the blades by taping a coin to one of them. Turn on the fan and hand on to the string at the loose end. With you other hand pinch the string and slide you hand down until a standing wave is produced. 5. Describe what happens as you move you hand. 6. What might happen if a different size weight is used? 7. As the tension increases, there will be changes in the length of the standing waves. http: //www. arborsci. c om/cool/soundwaves-goodvibrations-part-1

DISAPPEARING GLASS. 1. Put a small glass or beaker inside another larger one. 2. Fill the smaller glass with vegetable oil allowing it to overfill into the large one until it completely covers the smaller one. 3. 3. Ask the students to explain what happened to the smaller glass. Some liquids have an index of refraction very close to that of glass. When a glass object is lowered into the liquid, it almost disappears. Clean the glass thoroughly to remove any surface film. http: //www. education. com/sc iencefair/article/disappearingbeaker/ http: //www. sciencechannel. c om/tv-shows/headrush/videos/head-rushdisappearing-glass/

BUTTERED TOAST If a slice of buttered toast is accidentally brushed off a tabletop, does it usually land buttered side down? Yes, but why? This demo assumes that the toast slide is butter side up on a table of the usual height, then pushed gently over the table edge. The toast will begin rotation while one edge is still on the table edge, and continue that rotation all the way down. The moment of inertia of the toast about its rotation axis ensures that it will complete a half rotation in the time it takes to reach the floor. If it were dropped from twice that height it would complete a full rotation. The outcome has nothing to do with the toast being heavier on the buttered side. You can test this, if you are willing to clean up the mess, with a toast slice that begins its fall with buttered side down. It should land butter side up. Remember, in all cases to slide the toast off the table top. Don't just drop it from table height by hand. https: //www. lhup. edu/~dsima nek/scenario/demos. htm http: //mythbusterstheexhibition. com/scienc e-content/butter-side-up/

Is it a fresh egg or not? 1. Spin a fresh egg on the table. 2. Stop its rotation momentarily with your finger, then quickly release it. It resumes spinning for a bit. 3. Why does the egg continue to spin? *When you stop the shell abruptly, the yolk and white continue to rotate. If you release the shell before that rotation stops, viscous drag pulls the shell along with the yolk and white. http: //www. planetscience. com/categories/experiments/magic -tricks/2012/03/spinning-eggs. aspx

Balloon with rice krispies 1. 2. 3. 4. Put some rice krispies in a balloon. Blow up the balloon and tie it. Rub the balloon on a sweater or cloth. What happens to the rice krispies? Why? http: //weirdsciencekids. com/Ric e. Krispie. Static. Electricity. Balloon. html

Embroidery ring and coin. Balance an embroidery ring on a flower vase with a coin resting at the top. Quickly hit the ring so that the coin falls in the vase. Allow a student to try and most of the time the coin misses. Object at rest stays at rest. Depends on where the ring is hit. Inside less friction and the coins falls down. Outside increases friction and the coin flies away. http: //faculty. uncfsu. edu/grahi/inertiaexp. pdf http: //www. ellenjmchenry. com/homeschool -freedownloads/energymachinesgames/documents/Inertia. Physics. Lab. pdf

SODA-STRAW WHISTLE. 1. Snip off the edges of that end to form two free flaps of the straw. 2. Blow in that end. The end acts like the reed of an oboe. 3. Flatten the flaps more (or less) as necessary to produce the sound. 4. Different lengths give different pitch. Start with a long one, and snip off lengths with scissors, making it successively shorter. When it gets shorter than an inch or so, be careful not to snip your nose with the scissors. https: //www. lhup. e du/~dsimanek/sce nario/demos. htm

Farm kids used to make goose-feather or oat straw whistles. Snip off and discard the portion with the feathers, leaving only about a two inch piece. Make a diagonal cut at the closed end, raising up a portion of the shank so it looks like a miniature clarinet mouthpiece. Blow into it for a high-pitched sound. Can be concealed in the mouth. https: //www. lhup. edu/~dsimanek/scenario/ demos. htm

Remote control light 1. Many households have 5 or 6 remote controls laying around the house. Sometimes, it stops working and you don't know what happened. 2. Most remote controls use infrared light to transmit the signal. 3. The human eye cannot see this light, however a camera can. http: //www. wikih ow. com/Check-if -a-Remote. Control-is. Transmitting-an. Infrared-Signal

Vortex cannon and smoking gun Take a can, cut out the top and bottom, tape a piece of cardboard over one end, and cut a hole in the center of the cardboard. Tape a disk of thin card stock or heavy paper over the other end (or better yet, snip a balloon in half and stretch it across the other end. ) When you gently whack the covered end of your vortex launcher, a transparent ring of spinning air will shoot out of the hole. Aim the device at your face or arm, and you'll feel the puff of air when it hits your skin. Describe what is happening? What do you feel or see? The vortex rings can be made visible with a bit of smoke. I use stick incense, and just shove the end of the stick into the hole for awhile (don't set the cardboard on fire!!) 1 -gallon polyethelene milk jug. https: //en. wikipedi http: //www. sciencebobstore a. org/wiki/Air_vort. com/airzooka-air-cannon/ ex_cannon http: //www. sciencebobstore. co m/zero-blaster-smoke-ring-gun/

Stacked Energy Transfer Balls The stack of balls is dropped, the large ball hits the floor first. Describe what is happening with the energy involved When the balls are released they strike the floor in a series of almost elastic collisions which transfers all the energy to the lightest ball. Mechanics Linear Momentum Transfer http: //www. sciencebobstore. com/astroblaster-seismic-accelerator/

Spin-A-Ball Hoop Place a ball inside of the Spin-A-Ball hoop, gently flick your wrist and the ball magically spins inside of the circle ignoring Earth’s gravity. Our high quality Spin-A-Ball game uses Centrifugal Force to keep the ball in motion. It’s the same magical force that allows Amusement Rides and Roller Coasters to go upside down! Make up games to measure your time or perform stunts while the ball is in motion. http: //www. tintoyarcade. com/products/Spin-A-Ball. Game-Classic-Centrifuge-Toy. html

Lota Bowl 1. Pour all of the water out of the lota bowl until it's completely empty-or is it? 2. Pick up the bowl just minutes later and-voila!-more water magically pours out. 3. Where did the water come from? Repeat this amazing feat over and over. Students also learn about pressure, since the lota bowl is actually a bowl in a bowl-with two small holes strategically placed. One hole is on the inside and one on the outside. Control the volume of water poured by simply holding your finger over the outside hole when pouring. http: //www. magictricks. com/lota-bowlantique. html

Crack a whip 1. Where is the noise coming from? 2. What causes the noise? The crack a whip makes is produced when a section of the whip moves faster than the speed of sound creating a small sonic boom. https: //en. wikipedia. or g/wiki/Whipcracking

Bugle or Viking horn The mouthpiece simply gives the lips a place to vibrate, and harnesses the vibrations. http: //www. physics. umn. edu/outreach/pforc e/circus/waves. html

Why did this happen? Balloons are made up of lots of chains, called polymer chains that are so small they are invisible to the naked eye. On the sides of the balloon, these polymer chains are stretched to their limit. At the neck of the balloon the polymers are much less stretched, so when pierced with a knitting needle, there is enough room to allow the needle in between the chains without breaking them. http: //scifun. chem. wisc. edu/HOMEEXPTS/ needle. htm

Needle in Balloon 1. Insert a needle through a blown balloon without popping it. Pull it out. 2. Insert the needle into the balloon popping it. 3. Pass out balloons and needles for each to try. 4. In small groups discuss what happened in each case and share in the large group. http: //scifun. chem. wisc. edu/HOMEEXPTS/ needle. htm

Why are soap bubbles round? The surface tension of a bubble is like the stretch of a balloon. This stretch attempts to shrink the bubble or balloon to a very small size. Think of an uninflated balloon. When there is air trapped inside a bubble or balloon then it can't shrink too much because that will compress the air. So, the effect of the stretch if to make the bubble take a shape that has the smallest area (the amount of surface) for a given volume (the amount of air inside). I’ll blown some soap bubbles around the room. http: //simscience. org/membranes/intermediate/essay/why_bubbles_round 1. html

Wind tower and genecon Wind power and energy site: http: //www. need. org/

Balancing Bottle Board 1. Balance a 2 liter pop bottle in the balance board. 2. Ask student to describe what is happening. Basically this is a balancing trick. The hole in the board holds the neck of the soda bottle as it “appears to defy gravity”. It all comes down to center of gravity. When you place the bottle in the holder the center of the gravity is directly above the system allowing the bottle and board to balance perfectly. http: //newyorkscienceteacher. com/sci/files/usersubmitted/Balancing_Bottle_Board_Blueprints. pdf

Doppler Effect Demo 1. Throw the doppler device to someone and have them throw it back. 2. Describe what is heard. Doppler discovered a change in wave frequency for the observer as he moved closer or farther away from the sound. This change in wave frequency results in a volume and intensity change in the sound. When the sound is approaching, it is louder than the same sound as it recedes. When the sound is at the instant of passing by the observer, it is identical to its emitted frequency and volume. When the source and sensor are moving toward each other a higher pitch is heard and if they move away from each other a lower pitch is heard. http: //www. acs. psu. edu/drussell/Demos/do ppler/doppler. html

Black and White spinning disc History of this Illusion • The illusion is an example of the "Motion Aftereffect" phenomenon. Most people have probably experienced the motion aftereffect without knowing that there is a name for it. • http: //dogfeathers. com/java/spirals. html

Centripetal force and inertia. • The object is to get both marbles to rest in those two depressions—simultaneously. Tilting or shaking the puzzle does no good. You can easily get one marble into its hole, but any attempt to get the other one in just dislodges the first one. http: //www. lhup. edu/~dsimanek/toytricktea ser/centripetal. htm

Flip Ball—this is a variation of an old game called bilboquet. • To play you try to flip a bead or ball from a cup mounted on a wooden spring strip to an identical cup mounted on a base piece. http: //www. cubroundtabl e. com/assets/pdfsundry/Great-Salt-Lake. Council-Wood-puzzlesand-toys. pdf

Electro-Static Scientific Wand! • Scientifically speaking, the Fun. Fly. Stick is a compact Van de Graaff generator, capable of creating an electrical field strong enough to keep the included Mylar objects hovering in the air. https: //www. scientificso nline. com/product/funflystick? gclid=CJyk 6 Yjn 6 Mo. CFYVAa. Qod-l. AFq. Q

Whirly – The Twirling Sound Hose • As you twirl the tube, air molecules are launched out of the other end. The faster the twirl, the faster the molecules come flying out. http: //www. stevespanglersc ience. com/lab/experiments/ sound-hose/

The Electric Pickle • What happens in the Electric Pickle Experiment is that once a voltage (120 V) is placed across the pickle, there are Sodium anodes (Na+, electron expelling) and Chloride cathodes (Cl-, electron grabbing) that are excited to outside orbital levels of the atom. Just like a sodium vapor lamp, once the electric field charges the pickle, sodium atoms let go of an electron, causing a photon to be released once the haul tail back to lower energy levels in the atom. The result? Pickle light! http: //www. jimonlig ht. com/2013/08/26/ how-to-make-theelectric-pickleexperiment/

Alternating Current Demo • AC powered neon bulb demonstrates alternating current. Bulb flashes twice each cycle or 120 flashes per second. When at rest, bulb appears to be continuously illuminated. When rotated in a circle, flashes of light are obvious in a wonderful pattern of light and dark. Dazzling in a dark classroom! http: //www. physicstoolboxinc. com/pc-61 -2 -alternatingcurrent-demo-kit. aspx

Projectile Motion • Upwardly Launched Projectiles • I teach my students to break these launched projectile problems into two halves; the up half and the down half. We can solve every problem this way. The steps are basically the same for every problem. • Get Vx and Vy from the velocity and angle. • Get the time_up using Vy/g http: //www. splung. com/con tent/sid/2/page/projectiles http: //www. physicsclassroom. co m/Class/vectors/U 3 L 2 a. cfm