# Tag Info

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Method 1: Foucault Pendulum As user Rob asks, what is wrong with a short Foucault pendulum? There is a problem, but it can be overcome inexpensively, but with some DIY effort at home. The problem is that, by dint of imperfections in the suspending fibre and bob, no pendulum will swing in a plane even if the Earth were not rotating. Instead, the bob will ...

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I have been recently performing experiments using UVB (and UVA light) light. The personal protection I have been using have been a welder's mask (to protect the face) and sun glass like material for the eyes and sun protective clothing that did not leave any skin exposed (e.g. hands, arms etc). As mentioned in the comments, surround the experiment in a ...

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The only place where I have ever seen this done successfully, and actually heard the cancellation was in a room where there were no reflections from the walls or the floor (an anechoic chamber). In this case, the cancellation was so perfect that I couldn't hear anything. I took a couple steps laterally and then the sound returned. I was quite stunned. I ...

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When you run into a problem like this, there are several things to consider: Systematic error. For example, when you say "three, two, one, go" you never release exactly on "go" (plus, there is a time delay between when the person says "go" and when you hear it...). Other example: the floor is not level (as suggested by ACuriousMind). When you measure the ...

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If you exclude the forces of air resistance then this becomes the classic "Which falls faster? The baseball, or the cannonball?" In the case of the cannonball and the baseball, the cannonball will have negligibly more force applied to it, but will accelerate more slowly than the baseball. In the end, they will both hit the ground at the same time. Big ...

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Yes, adding mass to a toy car should at least in principle make it accelerate down a ramp faster. The total force on the car is in the "forward" direction, with magnitude $$F=m g \sin\theta\ -\ m g C_{rr}\cos\theta\ - \tfrac12 \rho v^2 C_D A\ ,$$ where $m$ is the car's mass, $g$ is the acceleration due to gravity at Earth's surface, $\theta$ is the angle ...

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To follow the information in Chris White's answer - essentially, you would want a medium that allows you to see the spectra. There are several online resources that could help you in this experiment, in particular, the CD spectrometer, which can be constructed simply and on that website, it shows several examples of how everyday light sources can be ...

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Lasers by definition only emit a single wavelength of light. You use one if you want that wavelength or if you want your photons to be in phase. You don't care about the photon phases, and you want to sample all wavelengths, so a laser is very much the wrong tool. If you just want collimation of the light, mirrors, lenses, or even just well-separated ...

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If you look at this video which claims to be a "world record spin", they claim they measured the speed (308 rpm!) with a "Sport Tach" - see for example review at http://figureskating.about.com/od/accessories/gr/sporttach.htm . Tried to follow links to their website - it seems their domain is for sale so I suspect they have gone out of business. When you ...

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If you don't want to do video, you could try with a smartphone. There are apps which can record the sensor measurements, including the accelerometer and the gyroscope. I have no idea how noisy the data will be for a skater, but if the device is firmly attached to her body close to her center of mass, it may deliver useful results. From there the sky is the ...

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In this link you can find a video analyzer tool. This tool works well with videos taken even on a smartphone, and is free and made for educational purposes. https://www.cabrillo.edu/~dbrown/tracker/ Have her hold a distinct red kerchief or ball in one hand. This way the tracker can easily track her spinning. You can get frequency as well as number of ...

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Here's an experiment with multiple parameters that simulates meteor impacts. Bonus if your daughter is interested in astronomy and space. Fill a box or basin with sand and smooth the surface. Then drop rocks onto the sand and measure the diameter or depth of the resulting crater (diameter is probably easier). You can vary the mass (different sized rocks) ...

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