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Combustion Volume vs. Heat Transfer and AM radio

  1. May 18, 2012 #1

    I have 2 problems that are currently bothering me, and I would enjoy help with either.

    The more immediate of these problems is with my family's gas stove. Whenever we need water to boil, we put the pot on and turn the burner all the way up. My father then comes in and turns it halfway down, and berates us for wasting gas (for the flames that leak over the side of the pot). My question is: How much thermal energy can reasonably be lost in such a situation? And does varying the amount of combusting gas significantly vary the amount of thermal energy being put into the pot, and the time it takes the water to boil?

    My second issue is this: I have an event coming up soon, that I would like to have music for, at concert-level volume. The issue is that I don't have concert-level speakers, nor am I willing to buy them. As an alternative, I thought it would be a good idea to convince some friends who will be attending the event to lend me their cars for the duration so I can broadcast music over an AM radio frequency. The issue is that I have no idea how to do this. Would it be possible to re-rig an AM radio to broadcast signals on a specific frequency, over a distance of more than a few feet?

    Thanks in advance for any help you can provide with either of these problems!
  2. jcsd
  3. May 18, 2012 #2
    1) Your father's opinion is the right one. Flames spreading well beyond the pot's bottom just waste energy.

    2) AM has a very limited bandwidth below 4 kHz whereas FM goes beyond 15 kHz. I'd go for FM. Even though simple radio transmitters can be found on the Web, broadcasting radio signals may require a license.
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