The RATTLER makes a great noise, but it is also a project that has a SPRING and a simple GEAR!
The paint stir-stick is the SPRING, the square with the four teeth is the GEAR! You can almost feel the tension in the spring by looking how it is bend from the base to the gear. A bend stick is like a loaded spring, it stores ENERGY, which is POTENTIAL ENERGY, it could be released any moment!
You control the timing by swinging the rattler counter clock wise holding it at the handle. The rattler body moves around the GEAR, and the teeth of the gear lift the stick up, one at the time, bending it more… When the SPRING escapes the tooth, it snaps back on the side of the square block: POTENTIAL ENERGY changes into IMPACT ENERGY, the impact makes a popping sound. Sound is also ENERGY, so energy changes from one kind into another kind. Where does the rattler energy come from? Well, what do you think? Just keep rattling and you will discover the ENERGY SOURCE! It is you: muscle energy! Go to the Energy module to learn more.
When you turn the rattler slowly you hear four clicks per turn, because there are four TEETH on the GEAR.
When your turn faster the clicks come faster and the PITCH of the sound changes. Pitch in this case is the number of clicks per unit of time. Ah well this might get a little out of hand… just enjoy the rattler.
Be careful though, leave yourself enough room to swing the rattler without hurting your friends or bystanders.
“Slinkies” are very flexible springs that move by using their elasticity and potential energy to move in strange ways, down the stairs, for example. You get them started by putting the spring on a tread and stretching it to put the other end on a tread lower than the first. Let go and because the Slinky goes from a higher level to a lower one it can use its POTENTIAL energy to get KINETIC energy while “walking” down the stairs. Look under the science of ENERGY to learn more about energy?
The person with two legs amputated runs on flexible blades that are part of his below-knee prosthesis . They mimic or work like our own legs when we run or walk. In this case the flexible blades are springs made of carbon fiber and cured epoxy resin. They are strong and flex. When he takes one step his body weight compresses the blade and his KINETIC energy changes partly into POTENTIAL energy in the spring. That makes it easier for him to push-off and gain kinetic energy and then in the next stride land on this other artificial leg, with the blade acting like a spring and the energy exchange repeats itself. Get it?
Here are all sorts of springs you can find in computers, toasters, bicycles, cars, airplanes…almost everything we use around us.
And here are several helical springs. Just a very strong piece of steel wire wound around a rod and that makes a spiral spring. You could try to make one with a coat hanger wire, clip the straight part off and wind it around a broomstick, then remove it and you have a spring. You need some help from a strong friend or an adult. The problem is when you stretch it too much it becomes longer and changes shape. That is why real springs are made from very hard steel that you can not easily bend, or from carbon fibers and epoxy.
Would it be fun to walk on these shoes with springs in them, you could make much bigger strides and jump higher, feels good… Put some flashing lights on them and you can give a show!
And what about Pogo sticks, how do they work?
Here is the design of a Pogo stick, notice the spring as the main part of the device. When you use it, the spring goes in and out, when you fall back down or jump up. Your weight pushes the spring IN and this means more POTENTIAL energy get stored in the spring. Then when you push-off, the spring pushes up, it stretches and this means the potential energy of the spring gives you KINETIC energy jumping upwards.