2. 33 1/3 RPM is that not exactly 200 degrees/sec. ? ;)
by jove, I think you're right! that'll learn me to worth to only a handful
of decimal points! ;)
would you consider #18 again? Or help me clarify the question?
19. Capacitance and Voltage Chris: watt seconds agreed!
The power in joules or watt/seconds of an electronic flash depends
primarily on two electrical factors. What are they?
I had my electronics hat on and it took over my brain and made me think:
power in watts is the relationship between current and voltage, a capacitor
sole purpose and function is to store and release current .. at a certain
voltage sure, but it's current release (taking into effect the resistance,
ripple current or inductance of the capacitor) that determines the power
flow rate - which in turn determines the duration of the flash and power
dissipation across a given time interval - couple this with the resistance
of the flash tube and any inductors in the circuit used to smooth (and
increase or reduce the duration of) the discharge, and really it's the
current and the impedence (resistance) that determines the output power and
duration.. often expressed as joules or watt seconds. I wouldn't have said
voltage, as too low and there's no discharge, too high and the amount and
rate of discharge won't change much, the light wavelength will tho .. which
is why flashes tend not to have any fluctuations or variations in voltage
permitted.
so current (delivered via a capacitor) and resistance (increasing /
decreasing flash duration)
well, that was my take ;) Also, thinking of continuous xenon discharge
lamps, Voltage aside for the reasons mentioned (it kinda has to be taken as
a constant, i.e. not a variable for the flash to perform as desired) it's
the current that determines the wattage - a low continous current gives a
low output, a high current, a high output.. and subsequently the relative
light output
ps, you can drive a flash with a teeeny current and a massive voltage,
actually taking the tube beyond it's internal resistance breakdown point and
get a very pure, very high output UV light source. very dangerous. nasty
stuff.
on #35 I was going for the simple answer - computer nerds!! :)
digital! eeez verrry specific! can't go mixing 1's and 0's! ;)
on #37 hs digital cameras fill up a buffer with images and then they
start replacing from oldest until buffer filled again so if you stop
recording when an event happens it runs for maybe 1/2 the buffer longer
and then stops. On playback you can play back frames that were recorded
before the stop signal arrived and thus look into the past! ;) ... so to
speak!
wow, something I never knew.. interesting!
30. 3.33
31. 1/10X ;)
now I'm totally in the dark
major errors on my part? let me know 'cause I still have time to fix them
before giving to students tomorrow afternoon!
nah, looks lovely to me - let me know what sort of arguments you get about
#35 though ;)
k
