ben@hpcvlx.HP.COM (Benjamin Ellsworth) (06/24/88)
First, I want to thank everyone who has taken the time to answer my
question. I both got the answer that I needed, and education in some
areas that I found interesting.
Now we get to the good part...
.. the answer is...
------DRUM ROLL-----
OK, ok, just give me a moment to wipe the egg off of my face.
30" or 2.5'
Award for simplest derivation going to similiar triangles (recipients
too numerous to mention).
Award for best clarifying example to Jack C. Morrison
"... Note that you could look at a solar eclipse with a wide-angle
or telephoto lens, but the moon would always cover the same area
as the sun. (kids, don't try this at home :-)"
This is the answer for the problem that I am trying to solve. I
received answers for other problems, and from them I learned alot.
Alas, I fell prey to curse of the over-educated, looking for a hard
answer to a simple question. I had considered similiar triangles, but
dismissed them as being too simple. Surely the focal length of the eye
came into play somewhere!
Until my next major brain failure,
Benjamin Ellsworth
ben%hpcvlx@hplabs.hp.com
or
{ backbone }!hplabs!hpcvlx!benmajka@grads.cs.ubc.ca (Marc Majka) (06/25/88)
In <350001@hpcvlx.HP.COM> ben@hpcvlx.HP.COM (Benjamin Ellsworth) writes: > A disc 3" in diameter at 10ft has the same perceived size as a > disc of what diameter at 100ft? Can you solve the equation: 3 X -- = --- 10 100 I knew you could!
alain@dgp.toronto.edu (Alain Fournier) (06/25/88)
In <350001@hpcvlx.HP.COM> ben@hpcvlx.HP.COM (Benjamin Ellsworth) writes: > A disc 3" in diameter at 10ft has the same perceived size as a > disc of what diameter at 100ft? The world is complicated enough as it stands, why use a crazy unit system that makes it worse? (by the way, the word "perceived" make the question considerably tougher than naive geometry, whether it was intended or not).
fnf@fishpond.UUCP (Fred Fish) (06/26/88)
In article <3293@ubc-cs.UUCP> majka@grads.cs.ubc.ca (Marc Majka) writes: >In <350001@hpcvlx.HP.COM> ben@hpcvlx.HP.COM (Benjamin Ellsworth) writes: >> A disc 3" in diameter at 10ft has the same perceived size as a >> disc of what diameter at 100ft? > >Can you solve the equation: > > 3 X > -- = --- > 10 100 Was this supposed to be a trick question? I perceive a 3" disk to have the same size, whether it is located 6" in front of my nose or across the room. :-) -Fred -- # Fred Fish, 1346 West 10th Place, Tempe, AZ 85281, USA # noao!nud!fishpond!fnf (602) 921-1113