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    Electronic Firework Ignition System

    I want to use a 50-pin cable to ignite e-matches connected to fireworks. The e-matches require about 1 Amp to ignite. The individual conducting wires in the cable are obviously very thin, and thus can't conduct a continuous 1 Amp current. My question though is this: can the very thin conducting...
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    Mechanics - mass on a circular ramp

    the problem we got in class was that an object of mass m was sliding down a quarter-circle ramp (or "quarter pipe) that had a radius a, and a coefficient of kinetic friction "mu". if the mass began down the ramp from rest and continued to the bottom, what would it's final velocity be? i had...
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    PA speaker question

    downward was a great idea, thanks... i'll see if it'll fit that way
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    PA speaker question

    i just purchased this PA speaker and am building the amp from a kit to power it. the question i have though is about mounting the speaker. i am going to mount it on my collision bar directly behind my grill. since it is directly behind the grill... if it rains, it will obviously get wet. i...
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    Making a spark gap transmitter

    thank you, that explanation and picture helped! josh
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    Making a spark gap transmitter

    the range does not need to be far at all. my teacher suggested only 50 v. i would probably use a battery or dc power supply. from what i've looked at so far, this is what i understand (or think i understand) about the kind i am going to build... a dc power supply, a switch (morse key), and...
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    Making a spark gap transmitter

    in one of my electronics classes, as a group we have to design and build a transmitter and receiver to transmit and receive morse code. we can only use a tesla coil and/or a spark gap for transmission. since we have 3 in our group... i am making the spark gap, someone else - a tesla coil, and...
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    5th grade brain teaser

    how is the boat docked? if it is far up on shore, not floating, and the tide level won't affect its position then i'd agree with the 12 minutes. however, if the boat is docked such that it is floating, then the tide won't move relative to the ladder.
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    Gas pressure and temperature relation

    just trying to understand how/why these two are proportional. if you compress a gas all the atoms and/or molecules would have less room to move around. so does the friction between these moving objects create heat? and if when gasses are compressed they heat up... why then when they are...
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    1.5 HP compressor on a 400 W inverter

    i have a 1.5 HP air compressor and a 400 W DC to AC inverter. i was wondering if i use this in my car what will happen. 1.5 HP is obviously close to 3 times more power than the inverter can supply. i would obviously keep my car running to keep the altnernator charging the battery. would the...
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    PA system

    loud enough for other people to hear, basically to have fun because i have money to waste. how would it compare to a cop car's pa system? they said it has a mod that would cost $100 and make it a lot louder. any comments on that?
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    PA system

    i want to buy a PA system for my car. the one i'm looking at has a 15W speaker... and it's the megaphone sort of speaker. i was wondering if someone could tell me whether this is a worthwhile system... if it will be loud enough... like the kind cops have in their cars. or does it just depend...
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    Flame thrower

    my friend and i recently made a flame thrower that was posted on other forums. it has a tank made from pvc that we pressurize to 80psi, the tank connects to a hose, through a vacuum breaker, through more hose, to a gun made from 1.5in. metal pipe. the gun has a valve where you can open it to...
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    Flame thrower

    my friend and i recently made a flame thrower that was posted on other forums. it has a tank made from pvc that we pressurize to 80psi, the tank connects to a hose, through a vacuum breaker, through more hose, to a gun made from 1.5in. metal pipe. the gun has a valve where you can open it to...
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    Simple code

    my friend put up a code on his away message and it was easy to figure out just guessing what it would be. then i put one up and i gave every letter in the alphabet a number... a=1, b=2, etc and then used 4x^2 + 2x + 7 to make them into different larger numbers. one of my smarter friends...
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    Terminal velocity for a bullet

    if a bullet is shot up in the air will it return to the ground as fast as it was shot up or will air resistance slow it down enough to not cause as much damage?
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    Battery memory

    in my physics class we learned about how batteries work. my teacher briefly talked about battery memory (how if you only let it discharge half way and recharge it and keep doing that cycle... the battery will think half way is empty) but he didn't give an explanation why. i'm somewhat familiar...
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    Stupid earth question

    if everyone in the world were to jump up at the same time would that affect the earth in any way?
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    Watering golf courses could make a surrounding area more humid

    i was wondering if watering golf courses could make a surrounding area more humid. the palm springs area in CA has golf courses all around and the golf courses use a million gallons of water to water their golf courses. would that make the palm springs area more humid?
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    How do planes fly inverted?

    i recently asked how airplanes work and i was give this answer: as velocity increases pressure decreases and the shape of the wing makes it so that the wind travels over the top of the wing faster than the bottom of the wing. so since there's a faster velocity on the top there is a lesser...
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    Light question

    my uncle was describing something that showed light traveling at a slow speed and i had no idea how it worked. he said it was a clear solid plastic like tube wrapped around in a coil and when you shined a light in one end you could watch it enter the coil, spin around the coil, and then exit...
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    0 - 60/horsepower calculator

    escort offers a passport g-timer that advertises being capable of just mounting to your windshield, plugging in your power cord and calculating 0 - 60 time, quarter mile time, peak horsepower, and g-forces. is all that possible from just a windshield mounted unit not connected (other than the...
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