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gorf250 wrote:

SciJ wrote: Couldn't you just have energy transfers that trigger other energy transfers? e.g. convert A to B, B hits a switch, allowing C to convert to D?

This is my interpretations of the rules, a series of energy CONVERSIONS that trigger the next conversion. I personally wouldn't see flipping a switch as the device transferring mechanical energy to electrical energy. However, this would make some transfers nearly impossible. Ex. transferring mechanical energy to ems.

chalker wrote:

twototwenty wrote:
Also, a quick question of my own: do you all think using a mechanical force to close a switch would actually be a mechanical-to-electrical conversion? Because the energy for the electricity is still coming from the battery, not the switch being closed.

here's something that might help you think about this better: 4.b says "directly transfers from one basic energy form to another".

First think about a wire hooked to a motor that's hooked to a switch connected to 2 wires. In this case you transfer electrical energy to mechanical via the motor, then use the mechanical energy on the switch to permit the passage of electricity.

Compare that to a wire hooked to a light bulb that's aimed at a photocell that's connected to 2 wires. In this case you transfer electrical energy to EM energy, then use the EM energy on the photocell to permit the passage of electricity. A photocell is essentially a switch (e.g. it doesn't have to be a 'solar' cell that outputs energy, but can be a 'phototransistor' type).

Is there any fundamental difference between the 2 situations? I don't believe there is. Of course this isn't the place for official clarifications as always....

twototwenty wrote: EDIT: Another quick question @chalker: Unofficially, of course, do you think that it would unhazardous lasers likely be allowed along with bulbs and leds?

twototwenty wrote:
Also a side note to chalker: in photocells, the energy from the photons is actually used to excite electrons; thus, energy is directly transferred from light to electricity, unlike with a mechanical device closing a switch.

EDIT: Another quick question @chalker: Unofficially, of course, do you think that it would unhazardous lasers likely be allowed along with bulbs and leds?

olympiaddict wrote:getting back to my (fairly sweeping before) questions about Chemical energy (forgive me, it was before 6AM)
suppose you use a different type of energy (say thermal) to provide the potential energy necessary to start a chemical reaction that releases energy, either mechanically or thermally or whatever you like.
The activation energy you put in does come out of the reaction, but it is accompanied by stored potential energy in the reactants
Should this count as a transfer?
I would hazard a guess that it does count. Otherwise I think chemical transfers would be very very difficult.

gorf250 wrote:This whole theoretical "blackbox" rule is still perplexing. For example, assume a lightbulb wouldn't count as electrical to ems, but would a just running current through a nichrome wire count? It's not like one requires more effort by the competitor, and each pretty much completes the transfer on its own. If a candle doesn't count as chemical to thermal, does a purchased string coated in wax count? What about just a string, or even a piece of wood? These would all produce the same result (heat), with very little effort by the student, so could any of these recieve points according to this "blackbox" rule?