# Tag Info

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There are a couple of ways of knowing the wavelength of laser pointer. 1) Using Snell'law (law of refraction): A light passing the border between two media whose refractive indexes vary. The incident light PO of wavelegth, $\lambda_{1}$ travelling in a media of refractive index, $n_{1}$ is refracted in to another media of refractive index, $n_{2}$, with a ...

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Summary: Based on provided data you will be able to comfortably bring the water to boiling point in 1 hour. The energy input required to heat the water alone is significantly less than the available energy and the difference is greater than typical thermal losses. ie Water_mass x delta_temperature x Water_specific_heat < energy input Details below. ...

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Your iPhone is a pretty good grating. I just did a simple experiment with an iPhone, a green laser pointer and a sheet of graph paper. This was the result: The display of the iPhone 6 has a resolution of 326 ppi - meaning we have a "grating spacing" of 25.4/326=0.0779 mm. Different models have different resolutions - make sure you find out what your ...

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If you've got a grating with known distance between the slits, you can use diffraction: let the light fall in perpendicular to the grating and place a screen a few meters further away. You'll find the maximum intensities (the light dots if you've got a grating with 100 or more slits per mm) under an angle of: $$\sin\theta_m = n\frac{\lambda}{d}$$ with $n$ ...

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The water heats up and expands as it is falling through the oil, due to density. the water is covered up and expands into steam blowing the oil away. boom.

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Measure the "thickness" of the fan blade. That is, the distance from the front to back of the twist in the blade. Now find how many times per second the blade rotates. Multiply that blade thickness (distance) by the number of times per second the blade moves through that position. It will give you an upper limit on air velocity.

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What is the explanation for this phenomena? "Water Hammer" https://en.wikipedia.org/wiki/Water_hammer There is a study from "Hasson and Peck", 1964, which explains "Thickness distribution in a sheet formed by impinging jets." It's all basically Bernoulli's equation; "Velocity -> pressure -> velocity" and then simply continuity. Anouther good source is the ...

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Sewage drains in houses should always have a "vent stack" - piping which extends up through the roof. The vent portion of the sewage plumbing has two purposes: to allow gases in the system to escape, and to provide a "suction break" so that traps (U-bends) don't have their contents sucked out when the pipe fills with flowing water (the water in a trap is ...

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That banana is a real radiator!

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Never seen that before, so I just tried it. Cool. I believe that the membrane between the yolk and the white is elastic, so when you first, gently, give the egg a little angular momentum, you are only spinning the white. As the yolk catches up the effective moment of inertia drops, and conservation of momentum therefor implies a higher angular velocity.

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Let's take this in steps. First - assume there is zero friction between the bottom block and the tower, and between the bottom block and the ground. If I move the block "infinitely quickly" the tower will have had no time to tilt at all, and it will drop vertically (and remain upright). This tells me there are two things to consider: the time take to ...

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Not sure anyone will look back at this, but I'd like to give an answer anyway! How do you not disturb the dishes when pulling a tablecloth out from under them? You're exactly right: this is about the inertia of the dishes and the forces on the dishes from the table cloth while the cloth is being pulled. Remember from physics that if we plot the velocity ...

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Let's solve this in two parts. First, I will calculate how fast you need to go at the bottom of the swing in order to be able to make a complete loop (without the rope going slack). Next, I will estimate whether you can achieve this speed by "pumping" - that is, moving your center of gravity around to increase your speed. Part 1: speed needed The velocity ...

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Heat flows into a cooler condition; cold does not flow into a warmer condition. The 'rate' of cooling is dependent upon the difference between the coffee and the surrounding, ambient temperature. That is, a very hot cup of coffee will cool "faster" than a just warm cup of coffee. As the very hot cup of coffee starts to approach room temperature the rate of ...

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normal "incoherent" light (white light from a bulb for example) is a world apart from coherent laser (Light Amplification by Stimulated Emission of Radiation) light white light is made up of many frequencies (colors) of light, moving outward in all directions from a point source laser light is made up of ONE color (read frequency) of light, moving in ONE ...

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