Author
Message
norman182
Boot
Joined: 16 Apr 2006 Posts: 14
#127 Card Houses main picture a tower of cards
card author kurt
text on card
i was waiting for violet - late as usual - after work one day, and got to building a tower out of spare perplex city cards. if all of the non-horizontal cards meet at a 30 deg angle; and i don't overlap any of the horizontal cards less than 2 cm; and i use 38 cards intotal... how tall is my tower?
This card has the 5 of hearts symbol on the bottom left hand corner
Posted: Sun Jul 30, 2006 8:26 am
ne0x
Veteran
Joined: 30 Jun 2006 Posts: 89 Location: Ottawa, Canada
Draw a picture!
Spoiler (Rollover to View):
I used 148mm as the height of the cards, and 0.5mm as the thickness.
Combined with my diagram and some trig, I come up with about 575mm.
It will depend on how accurate an answer they want.
Posted: Sun Jul 30, 2006 12:11 pm
DarkHuman
Unfettered
Joined: 19 Apr 2006 Posts: 638 Location: Florida
i get 23" or 584.2 mm. Set up the 38 cards myself.
__1
/\/\4
____3
/\/\/\ 6
_____4
/\/\/\/\8
______5
/\/\/\/\/\10
_________________
Playing ->WLOG
Posted: Sun Jul 30, 2006 7:47 pm
Cinana
Boot
Joined: 02 Jun 2006 Posts: 62 Location: Washington State, USA
Actually, I believe that is too many cards.
I studied this while at work today, and came up with this layout.
Spoiler (Rollover to View):
/\ (2)
___ (1)
/\/\ (4)
____ (2)
/\/\/\ (6)
_____ (2)
/\/\/\/\ (
_______ (3)
/\/\/\/\/\ (10)
And because typing it in is hard to get them centered... remember, the cards can't be less than 2cm layered.
Also, remember that the cards standing on end don't actually measure 14.8 cm when they are leaning at a 30 degree angle(x). its actually a bit smaller.
so when you have figured out x, then you times it by the tiers. Now, if MC is going to be really snibberish, and make us take into account the thickness of the card...well then, this shouldn't be a green card.
Now if I had the card, I would put in my answer as soon as they unlock the keycodes, alas, I won't get them until Tuesday.
If MC wants it in inches, or cm, is anyones guess, but I am going to have to go with
Spoiler (Rollover to View):
64.5cm
Posted: Sun Jul 30, 2006 11:45 pm
Cinana
Boot
Joined: 02 Jun 2006 Posts: 62 Location: Washington State, USA
hmm...maybe i did that wrong.
I don't have the patience to try to make these cards stand still while I try to stack them, but after some measuring, you can not stand the cards long side standing, and expect to get a base card to stay on top.
So, after much frustration at my husband (he's telling me that I have it right, but after physically showing him, he's shut up)
you must lay the cards long side on their sides for the 30 degree angle to work.
the answer then becomes
Spoiler (Rollover to View):
46.5cm
Posted: Mon Jul 31, 2006 12:18 am
KingOfWrong
Boot
Joined: 05 May 2006 Posts: 45
Remember, the cards meet at 30 degrees, which means they're at 15 degrees to the vertical - trigonometry only works on right-angled triangles, after all.
Spoiler (Rollover to View):
So each layer has a height of 148mm x cos(15) ~= 143mm
Posted: Mon Jul 31, 2006 1:57 am
ne0x
Veteran
Joined: 30 Jun 2006 Posts: 89 Location: Ottawa, Canada
Redrew my picture...
It looks like Cinana's now, and I get:
Spoiler (Rollover to View):
717mm
Of course it depends on them all meeting a exactly 30°, if it's off by a degree the height goes up or down by a mm or two. Then there's the thickness of the cards to consider, and what happens where the cards overlap???
"What's that Mr. Occam?"...
Right, the simplest solution... Wait until I actually receive this card, and go try some numbers.
Posted: Mon Jul 31, 2006 8:11 am
thereverendeg
Veteran
Joined: 16 Jul 2006 Posts: 74 Location: Rochester, NY
Confirmed Solve I can confirm that the following is accepted:
Spoiler (Rollover to View):
72
Posted: Mon Jul 31, 2006 2:19 pm
Cinana
Boot
Joined: 02 Jun 2006 Posts: 62 Location: Washington State, USA
I asked my friend who is the math whiz to check my work, and I was certainly wrong...However, I was not that far off. Misunderstood mostly.
LOL
After doing the math the correct way, the final answer is what thereverendeg said, if you round up. To 3 decimal places the answer would have also been 71.479.
So, don't mind me...I am just mathematically challenged.
Posted: Mon Jul 31, 2006 11:18 pm
xandert_86
Boot
Joined: 14 Apr 2006 Posts: 16 Location: Where I Be
Okay, it may have been a while since I've done proper maths, but I thought my basic trig was okay - S
o
h
C
a
h
T
o
a
Spoiler (Rollover to View):
I measuerd the cards at 147mm tall/long. Call this l
If the cards meet at 30
o
then, as has been said, the angle with the vertical (h ) is 15
o
.
The distance between two 'peaks' = 2(base of right angled triangle)
= 2(l sin15)
= 2(147sin15)
= 2(38.046....)
= 76.093mm (3d.p.)
If a card is 147mm (which it is) a single card cannot possibly cover the distance over 3 'peaks' in the tower beacause 147 < 2*76=152
2 cards can cover the distance of 3 'peaks', but not 4. (228 < 290 < 304)
3 cards can cover both 4 and 5 'peak' levels. 304 < 433 >380
Using this, a 5 tier house would require 39 cards:
/ \ 2+
__ 1+
/ \ / \ 4+
_____ 2+
/ \ / \ / \ 6+
________ 3+
/ \ / \ / \ / \ 8+
__________ 3+
/ \ / \ / \ / \ / \ 10 = 39
The vertical height of each tier = 147cos15
= 141.991...
And so four tiers = 567.964mm (3d.p.)[/i]
Turns out my answer very much isn't the accepted one. Can someone please point out where my rusty maths went too rusty?
Posted: Wed Aug 02, 2006 12:05 pm
ne0x
Veteran
Joined: 30 Jun 2006 Posts: 89 Location: Ottawa, Canada
xandert_86 wrote:
If a card is 147mm (which it is) a single card cannot possibly cover the distance over 3 'peaks' in the tower beacause 147 < 2*76=152
2 cards can cover the distance of 3 'peaks', but not 4. (228 < 290 < 304)
3 cards can cover both 4 and 5 'peak' levels. 304 < 433 >380
...
Turns out my answer very much isn't the accepted one. Can someone please point out where my rusty maths went too rusty?
Consider that the cards overlap by at least 2cm, and have a closer look at how many you need for roofs. You're on the right track though.
At worst, grab 38 cards and start building.
Posted: Wed Aug 02, 2006 1:16 pm
Cinana
Boot
Joined: 02 Jun 2006 Posts: 62 Location: Washington State, USA
My diagram that I wrote up top is the correct diagram. I noticed you only put "4 tiers". Ne0X said it right. Have a look at the roofs.
You are very very close to the correct answer. Just missing one aspect. Then after you have come up with the answer (yours may come with figure with 3 decimal places, just round up.
Good luck.
Posted: Thu Aug 03, 2006 1:20 pm
mDuo13
Greenhorn
Joined: 03 Aug 2006 Posts: 9 Location: San Jose, CA
So I took photos. The tallest one I could make with 38 cards was a little short of the theoretical maximum - apparently I overlapped a little much on the horizontal cards, and the angles of some pairs were too wide - but it was good times overall. Thanks to whoever had the accepted answer. I love doing this stuff, but I hate having to fuss over their specific answers, and I wasn't about to start doing all the math (though I could ... I just didn't want to).
Anyway, enjoy. The first pic is the tower with 38 cards. The second is 40 cards, but the proper number of levels. Sorry about the blur; my camera's batteries died midway through taking the pictures. (That's also why I didn't have room to clean the mess out of the picture.)
Description
38-card short tower
Filesize
68.22KB
Viewed
3037 Time(s)
Description
40-card tall tower
Filesize
47.21KB
Viewed
3049 Time(s)
Posted: Thu Aug 03, 2006 2:50 pm
ne0x
Veteran
Joined: 30 Jun 2006 Posts: 89 Location: Ottawa, Canada
That rocks!
There ought to be a gallery for pictures of solutions to cards. There are more than one that involves baking, building or making something.
Posted: Thu Aug 03, 2006 5:57 pm
bobonacus
Greenhorn
Joined: 22 Apr 2006 Posts: 4 Location: berkshire
great puzzle ... and a great card stack
years since i've used soh cah toa
see http://www.mathsrevision.net/gcse/pages.php?page=39
Spoiler (Rollover to View):
taking the card to be 148mm
height of each 2 card tower is 148 cos 15
distance at the bottom of a 2 card tower is two times 148 cos 75
you can then work out how many stacks
Posted: Thu Aug 03, 2006 8:30 pm
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