Motion/Energy

Vibrating pennies – conduction experiment

Vibrating pennies Take a bottle with a narrow opening. The opening should be just about the size of a penny. Dip a penny in a bowl of ice water. Hold the neck of the bottle in the ice water for a few seconds too. Place the penny over the mouth of the jar. Place some oil around the bottles opening or on the penny in order to provide a completely air tight seal. Now hold bottle in your hands and carefully observe the penny. It should begin bouncing around. Rubbing the bottle will increase the heat even more. Remember - heat causes things to expand (or get larger). Cold causes things to contract (or get smaller). The heat from your hands is transferred through conduction…
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Motion/Energy

Off to the races (with jars – that is) – friction experiment

Off to the races (with jars - that is) In this experiment we race two jars - one full of water and the other empty (actually it's full of air). Before racing the jars, take a guess as to which jar will finish first. Maybe make a little wager with Fill one of your jars with water. Put lids on both of the jars. Make sure the lid on the jar full of water is on tight. Place a three-ring binder on a level floor and start both of the jars from the top of the 'ramp'. Which one gets to the bottom of the ramp first? Which one rolls the farthest? Were you surprised at the outcome? When the race begins, the jar full…
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Motion/Energy

Moving Magical Marbles with More Momentum than Most

Moving Magical Marbles with More Momentum than Most Inertia means that a rolling ball on a smooth, level surface will roll forever if nothing stops it. In fact, friction and air pushing against the moving ball will eventually bring it to a stop. But interesting things happen when a motionless object gets in the way of a moving one. Try this experiment and see for yourself. Tape the yardsticks to a tabletop so they're parallel and about 1/2 inch apart (if you are under 5 then we feel compelled to remind you that mom and dad will not appreciate the artistic appeal of 2 yardsticks glued to the kitchen table). Put 2 marbles in the middle of the sticks (our 'track') a few inches apart.…
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Motion/Energy

Milk carton water wheel

Milk carton water wheel Ever held a toy under your running bath water? Did it spin or twist away from you? This is explained by a law proposed by a guy named Sir Isaac Newton. Specifically the law states that 'for every action there is a equal and opposite reaction'. You know, kind of like when you smack your big brother you know you're going to get smacked back. OK, so maybe that's not such a great example. Here's one that will aptly demonstrate Newton's law. Poke a hole in the bottom left hand corner of each of the four faces of a half-gallon, paper milk carton. Now poke a hole in the top flap of the milk carton. Tie a string through this hole.…
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Motion/Energy

Floating Ping Pong Balls

Floating Ping Pong Balls Gravity is a mysterious thing. We experience its effects every day but never really think about. Not enough gravity and we’d be floating around in space. Too much gravity and we’d be flattened like a pancake. Luckily, the gravitational pull is just right here on Earth. It keeps us comfortably anchored to the ground. Still, it helps to understand that with regards to gravity, there are opposing forces at work. Another principle demonstrated in this experiment is the Bernoulli Principle. The Bernoulli Principle states that as an air stream (or fluid) speeds up, a decrease in pressure occurs. Fast moving air will cause a drop in air pressure (relative to the air pressure outside the column of moving air). Turn hair…
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