Can you solve the human cannonball riddle? - Alex Rosenthal

936,622 views ใƒป 2021-11-22

TED-Ed


ืื ื ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ืœืžื˜ื” ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ.

ืชืจื’ื•ื: Ido Dekkers ืขืจื™ื›ื”: zeeva livshitz
00:06
They call you the human cannonball,
0
6669
2795
ื”ื ืงื•ืจืื™ื ืœื›ื ื”ืคื’ื– ื”ืื ื•ืฉื™,
00:09
but youโ€™re really more of a pinball person.
1
9464
2961
ืื‘ืœ ืืชื ื‘ืืžืช ื™ื•ืชืจ ืื ืฉื™ื ืฉืœ ืคื™ื ื‘ื•ืœ.
00:12
Your act involves flying through a dozen rings of fire,
2
12425
4379
ื”ืžื•ืคืข ืฉืœื›ื ื›ื•ืœืœ ื˜ื™ืกื” ื“ืจืš ืขืฉืจื•ืช ื˜ื‘ืขื•ืช ืืฉ,
00:16
bouncing through a trampoline course,
3
16804
2336
ืงืคื™ืฆื” ื“ืจืš ืžืกืœื•ืœ ื˜ืจืžืคื•ืœื™ื ื•ืช,
00:19
and catching the trapezist in the grand finale.
4
19140
3670
ื•ืœืชืคื•ืฉ ืืช ืืžื ื™ืช ื”ื˜ืจืคื– ื‘ืกื™ื•ื ื”ื’ื“ื•ืœ.
00:23
Your cannon has metal coils that accelerate you to the perfect speed.
5
23061
4879
ืœืชื•ืชื— ืฉืœื›ื ื™ืฉ ืกืœื™ืœื™ ืžืชื›ืช ืฉืžืื™ืฆื™ื ืืชื›ื ืœืžื”ื™ืจื•ืช ื”ืžื•ืฉืœืžืช.
00:28
At least itโ€™s supposed to.
6
28232
1961
ืœืคื—ื•ืช ื”ื•ื ืืžื•ืจ.
00:30
Todayโ€™s pre-flight test fails dramatically,
7
30193
3795
ื ืกื™ื•ืŸ ื˜ืจื•ื ื”ื˜ื™ืกื” ืฉืœื›ื ื”ื™ื•ื ื›ืฉืœ ื“ืจืžื˜ื™ืช,
00:33
and upon inspection, this is a clear act of sabotage:
8
33988
4546
ื•ื”ื‘ื“ื™ืงื” ืžื•ื›ื™ื—ื”, ืฉื‘ืจื•ืจ ืฉื–ื• ื—ื‘ืœื”:
00:38
someone amped the power up to the max.
9
38534
3212
ืžื™ืฉื”ื• ื”ื’ื‘ื™ืจ ืืช ื”ื›ื•ื— ืœืžืงืกื™ืžื•ื.
00:41
Itโ€™s too late to abort the launch;
10
41954
2211
ื–ื” ืžืื•ื—ืจ ืžื“ื™ ืœื‘ื˜ืœ ืืช ื”ืฉื™ื’ื•ืจ;
00:44
the trapezist will plummet if you donโ€™t catch him in a few minutes.
11
44165
3754
ืืžื ื™ืช ื”ื˜ืจืคื– ืชืฆื ื— ืื ืœื ืชืชืคืฉื• ืื•ืชื” ืชื•ืš ื›ืžื” ื“ืงื•ืช.
00:47
So youโ€™d better get fixing.
12
47919
1918
ืื– ื›ื“ืื™ ืฉืชืชืงื ื• ืื•ืชื•.
00:50
The cannon was invented by your eccentric mentor,
13
50838
3003
ื”ืชื•ืชื— ื”ื•ืžืฆื ืขืœ ื™ื“ื™ ื”ืžื ื˜ื•ืจ ื”ืžื•ื–ืจ ืฉืœื›ื,
00:53
and as usual, his instructions leave something to be desired.
14
53841
3796
ื•ื›ืจื’ื™ืœ, ื”ื”ื•ืจืื•ืช ืžืฉืื™ืจื•ืช ืฉืืœื•ืช.
00:58
The cannonโ€™s electromagnet is powered by energy cells
15
58179
3962
ื”ืืœืงื˜ืจื• ืžื’ื ื˜ ืฉืœ ื”ืชื•ืชื— ืžื•ืคืขืœ ืขืœ ื™ื“ื™ ืชืื™ ืื ืจื’ื™ื”
01:02
located in 16 chambers on two levels.
16
62141
3712
ืฉืžืžื•ืงืžื™ื ื‘ 16 ืชืื™ื ื‘ืฉืชื™ ืจืžื•ืช.
01:06
Each level is a hollowed out square, with three chambers to a side.
17
66104
4713
ื›ืœ ืจืžื” ื”ื™ื ืจื™ื‘ื•ืข ืžืจื•ืงืŸ, ืขื ืฉืœื•ืฉื” ืชืื™ื ื‘ื›ืœ ืฆื“.
01:11
The acceleration is survivable if:
18
71275
2503
ื ื™ืชืŸ ืœืฉืจื•ื“ ืืช ื”ืชืื•ืฆื” ืื:
01:13
there are twice as many energy cells in the upper level as in the lower level.
19
73778
5255
ื™ืฉ ืคื™ ืฉื ื™ื™ื ืชืื™ ืื ืจื’ื™ื” ื‘ืจืžื” ื”ืขืœื™ื•ื ื” ืžืืฉืจ ื‘ื ืžื•ื›ื”.
01:19
Every chamber has 1 to 3 energy cells.
20
79033
3587
ื‘ื›ืœ ื—ืœืœ ื™ืฉ 1 ืขื“ 3 ืชืื™ ืื ืจื’ื™ื”.
01:22
And each side of the cannon, made of 6 chambers, has 11 energy cells.
21
82829
4921
ื•ืœื›ืœ ืฆื“ ืฉืœ ื”ืชื•ืชื—, ืฉืขืฉื•ื™ ืž 6 ื—ืœืœื™ื, ื™ืฉ 11 ืชืื™ ืื ืจื’ื™ื”.
01:28
Your mentor designed the cannon to use a certain number of energy cells,
22
88126
4212
ื”ืžื ื˜ื•ืจ ืฉืœื›ื ืชื›ื ืŸ ืืช ื”ืชื•ืชื— ืœื”ืฉืชืžืฉ ื‘ืžืกืคืจ ืžืกื•ื™ื™ื ืฉืœ ืชืื™ ืื ืจื’ื™ื”,
01:32
but when the shipment arrived, it was 3 short.
23
92338
3128
ืื‘ืœ ื›ืฉื”ืžืฉืœื•ื— ื”ื’ื™ืข, ื”ื™ื• ื—ืกืจื™ื ืฉืœื•ืฉื”.
01:35
So he made all of those conditions work with this reduced number,
24
95508
4504
ืื– ื”ื•ื ื’ืจื ืœื›ืœ ื”ืชื ืื™ื ื”ืืœื” ืœืขื‘ื•ื“ ืขื ืžืกืคืจ ืžื•ืคื—ืช,
01:40
and it fired perfectly.
25
100012
1794
ื•ื”ื•ื ื™ืจื” ื‘ืžื“ื•ื™ื™ืง.
01:42
Thatโ€™s the amount youโ€™ll need.
26
102265
1918
ื–ื• ื”ื›ืžื•ืช ืฉืชืฆื˜ืจื›ื•.
01:44
Too many, or too few, and you and the trapezist are doomed.
27
104392
4629
ื™ื•ืชืจ ืžื“ื™, ืื• ืคื—ื•ืช ืžื“ื™, ื•ืืชื ื•ืืžื ื™ืช ื”ื˜ืจืคื– ืื‘ื•ื“ื™ื.
01:49
How many energy cells should you use, and where?
28
109897
3545
ื‘ื›ืžื” ืชืื™ ืื ืจื’ื™ื” ืืชื ืฆืจื™ื›ื™ื ืœื”ืฉืชืžืฉ, ื•ืื™ืคื”?
01:53
Pause here to figure it out yourself. Answer in 3
29
113693
2544
ืขื™ืฆืจื• ืคื” ื›ื“ื™ ืœื”ื‘ื™ืŸ ื‘ืขืฆืžื›ื. ืชืฉื•ื‘ื” ืขื•ื“ 3
01:56
Answer in 2
30
116237
2127
ืชืฉื•ื‘ื” ืขื•ื“ 2
01:58
Answer in 1
31
118364
2586
ืชืฉื•ื‘ื” ืขื•ื“ 1
02:01
The first step in this puzzle is to narrow the options.
32
121033
3796
ื”ืฉืœื‘ ื”ืจืืฉื•ืŸ ื‘ื—ื™ื“ื” ื”ื–ื• ื”ื™ื ืœืฆืžืฆื ืืช ื”ืืคืฉืจื•ื™ื•ืช.
02:04
Letโ€™s focus on rule 3 in isolation.
33
124954
2878
ื‘ื•ืื• ื ืชืžืงื“ ื‘ื—ื•ืง ื”ืฉืœื™ืฉื™ ืœื‘ื“ื•.
02:08
We could put 11 cells in these two corners and fulfill it with just 22 total cells,
34
128791
6215
ื ื•ื›ืœ ืœืฉื™ื 11 ืชืื™ื ื‘ืฉืชื™ ื”ืคื™ื ื•ืช ื”ืืœื• ื•ืœื”ืคืขื™ืœ ืื•ืชื• ืขื ืจืง 22 ืชืื™ื ื‘ืกืš ื”ื›ืœ,
02:15
because adjacent sides share corners.
35
135006
2544
ื‘ื’ืœืœ ืฉืฆื“ื“ื™ื ืฉื•ื ื™ื ื—ื•ืœืงื™ื ืคื™ื ื•ืช.
02:17
But if we put 11 in the middle chambers, we could have 44 cells.
36
137967
4588
ืื‘ืœ ืื ื ืฉื™ื 11 ื‘ื—ืœืœื™ื ื”ืžืจื›ื–ื™ื™ื, ื™ื•ื›ืœื• ืœื”ื™ื•ืช ืœื ื• 44 ืชืื™ื.
02:22
The answer must be in the range bounded by those extremes.
37
142722
4045
ื”ืชืฉื•ื‘ื” ื—ื™ื™ื‘ืช ืœื”ื™ื•ืช ื‘ื˜ื•ื•ื— ืฉื‘ื™ืŸ ืฉื ื™ ื”ืงื™ืฆื•ื ื™ื ื”ืืœื”.
02:27
We can use the other rules to refine our options further.
38
147476
4672
ืื ื—ื ื• ื™ื›ื•ืœื™ื ืœื”ืฉืชืžืฉ ื‘ื—ื•ืงื™ื ื”ืื—ืจื™ื ื›ื“ื™ ืœืขื“ืŸ ืืช ื”ืืคืฉืจื•ื™ื•ืช ืฉืœื ื• ืขื•ื“.
02:32
Since there are twice as many cells in the upper level,
39
152148
3086
ืžืื—ืจ ื•ื™ืฉ ืคื™ ืฉื ื™ื™ื ื™ื•ืชืจ ืชืื™ื ื‘ืจืžื” ื”ืขืœื™ื•ื ื”,
02:35
the total cells must be a multiple of 3.
40
155234
3170
ืกืš ื”ืชืื™ื ื—ื™ื™ื‘ ืœื”ื™ื•ืช ื›ืคื•ืœื” ืฉืœ 3.
02:38
Now, because of rule 4,
41
158696
1835
ืขื›ืฉื™ื•, ื‘ื’ืœืœ ื—ื•ืง 4,
02:40
we need to find two consecutive multiples of 3 that can meet all the conditions.
42
160531
5464
ืื ื—ื ื• ืฆืจื™ื›ื™ื ืœืžืฆื•ื ืฉืชื™ ื›ืคื•ืœื•ืช ืจืฆื•ืคื•ืช ืฉืœ 3 ืฉื™ื›ื•ืœื•ืช ืœืžืœื ืืช ื”ืชื ืื™ื.
02:46
Up to this point we havenโ€™t used the rule that each chamber must have 1 to 3 cells.
43
166287
5839
ืขื“ ืœื ืงื•ื“ื” ื–ื• ืœื ื”ืฉืชืžืฉื ื• ื‘ื—ื•ืง ืฉื›ืœ ื—ืœืœ ื—ื™ื™ื‘ ืœื”ื›ื™ืœ 1 ืขื“ 3 ืชืื™ื.
02:52
It tells us that the minimum for the lower level is 8 cells,
44
172585
3920
ื”ื•ื ืื•ืžืจ ืœื ื• ืฉื”ืžื™ื ื™ืžื•ื ืœืจืžื” ื”ืชื—ืชื•ื ื” ื”ื™ื 8 ืชืื™ื,
02:56
in which case, by rule 1, the upper level would have 16.
45
176505
4380
ื‘ืžืงืจื” ื”ื–ื”, ืœืคื™ ื—ื•ืง 1 ื‘ืจืžื” ื”ืขืœื™ื•ื ื” ื™ื”ื™ื• 16.
03:01
On every side, the lower level would account for 3 of the 11 cells,
46
181302
4755
ื‘ื›ืœ ืฆื“, ื”ืจืžื” ื”ื ืžื•ื›ื” ืชื›ื™ืœ 3 ืžืชื•ืš 11 ื”ืชืื™ื,
03:06
so the upper would have to have 8.
47
186057
2586
ืื– ื”ืขืœื™ื•ื ื” ืชื›ื™ืœ 8.
03:09
But if two opposite sides had 8,
48
189018
2753
ืื‘ืœ ืื ื‘ืฉื ื™ ื”ืฆื“ื“ื™ื ื”ืžื ื•ื’ื“ื™ื ื”ื™ื• 8,
03:11
that would be the upper levelโ€™s entire 16, not leaving any for these two chambers.
49
191771
5755
ื–ื” ื™ื”ื™ื” ื›ืœ ื” 16 ืฉืœ ื”ืจืžื” ื”ืขืœื™ื•ื ื”, ื•ืœื ื™ืฉืื™ืจ ืœืฉื ื™ ื”ืชืื™ื ื”ืืœื”.
03:17
So 24 is out.
50
197693
1919
ืื– 24 ื‘ื—ื•ืฅ.
03:20
Letโ€™s look at the other extreme.
51
200696
2169
ื‘ื•ืื• ื ื‘ื™ื˜ ื‘ืงื™ืฆื•ืŸ ื”ืฉื ื™.
03:23
The upper level can have at most 3 times 8, or 24 cells,
52
203074
5172
ื‘ืจืžื” ื”ืขืœื™ื•ื ื” ื™ื›ื•ืœื™ื ืœื”ื™ื•ืช ื”ื›ื™ ื”ืจื‘ื” 3 ืคืขืžื™ื 8, ืื• 24 ืชืื™ื,
03:28
which would give a total of 36.
53
208246
2460
ืžื” ืฉื™ืชืŸ ืกืš ืฉืœ 36.
03:30
That eliminates 39 and 42.
54
210915
3086
ื–ื” ืžื‘ื˜ืœ ืืช 39 ื• 42.
03:34
With 36, if we had 3 cells in each chamber,
55
214252
3712
ืขื 36, ืื ื”ื™ื• ืœื ื• ืฉืœื•ืฉื” ืชืื™ื ื‘ื›ืœ ื—ืœืœ,
03:38
each side of the upper level would already have 9 of its 11 cells,
56
218130
4797
ื‘ื›ืœ ืฆื“ ืฉืœ ื”ืจืžื” ื”ืขืœื™ื•ื ื” ื›ื‘ืจ ื™ื”ื™ื• 9 ืžืชื•ืš 11 ื”ืชืื™ื ืฉืœื•,
03:42
meaning weโ€™d have to leave empty chambers on the lower level.
57
222927
3253
ืžื” ืฉืื•ืžืจ ืฉื ืฆื˜ืจืš ืœื”ืฉืื™ืจ ื—ืœืœื™ื ืจื™ืงื™ื ื‘ืจืžื” ื”ืชื—ืชื•ื ื”.
03:46
So 36 is also out.
58
226555
2420
ืื– ื’ื 36 ื‘ื—ื•ืฅ.
03:49
What about 33?
59
229392
1376
ืžื” ื‘ื ื•ื’ืข ืœ 33?
03:50
We know we donโ€™t want any sides with all 3โ€ฒs,
60
230977
2836
ืื ื—ื ื• ื™ื•ื“ืขื™ื ืฉืื ื—ื ื• ืœื ืจื•ืฆื™ื ืืฃ ืฆื“ ืขื ื›ื•ืœื• 3,
03:53
so we can place 2โ€ฒs at opposite corners of the upper level.
61
233813
3753
ืื– ืื ื—ื ื• ื™ื›ื•ืœื™ื ืœืฉื™ื 2 ื‘ืคื™ื ื•ืช ื”ืžื ื•ื’ื“ื•ืช ืฉืœ ื”ืจืžื” ื”ืขืœื™ื•ื ื”.
03:58
Now we have 8 of 11 cells per side.
62
238150
3087
ืขื›ืฉื™ื• ื™ืฉ ืœื ื• 8 ืžืชื•ืš 11 ืชืื™ื ื‘ื›ืœ ืฆื“.
04:01
So we could place exactly 1 cell in each lower chamber...
63
241404
4170
ืื– ื ื•ื›ืœ ืœืฉื™ื ื‘ื“ื™ื•ืง ืชื 1 ื‘ื›ืœ ื—ืœืœ ื‘ืจืžื” ื”ืชื—ืชื•ื ื”...
04:05
but that would fall short of the lower levelโ€™s required 11.
64
245574
3921
ืื‘ืœ ื–ื” ืœื ื™ืกืคืง ืืช ื” 11 ื”ื“ืจื•ืฉื™ื ื‘ืจืžื” ื”ืชื—ืชื•ื ื”.
04:09
That leaves only two options: 30 and 27,
65
249787
4046
ื–ื” ืžืฉืื™ืจ ืจืง ืฉืชื™ ืืคืฉืจื•ื™ื•ืช: 30 ื• 27,
04:13
which must work by process of elimination,
66
253833
2711
ืฉื—ื™ื™ื‘ื™ื ืœืขื‘ื•ื“ ืœืคื™ ืชื”ืœื™ืš ื”ืืœื™ืžื™ื ืฆื™ื”,
04:16
and 27 is the one you should use.
67
256544
2502
ื• 27 ื”ื•ื ื–ื” ืฉืืชื ืฆืจื™ื›ื™ื ืœื”ืฉืชืžืฉ ื‘ื•.
04:19
To total 9, the lower level must have seven 1โ€ฒs and one 2.
68
259130
4421
ืœืกืš ืฉืœ 9, ืœืจืžื” ื”ืชื—ืชื•ื ื” ื—ื™ื™ื‘ื™ื ืœื”ื™ื•ืช ืฉื‘ืขื” 1 ื• 2 ืื—ื“.
04:23
If you put the 2 in a middle chamber, the upper level would have too many cells.
69
263759
4838
ืื ืชืฉื™ืžื• ืืช ื” 2 ื‘ืžืจื›ื– ื”ืชื, ื‘ืจืžื” ื”ืขืœื™ื•ื ื” ื™ื”ื™ื• ื™ื•ืชืจ ืžื“ื™ ืชืื™ื.
04:28
So the 2 has to go into a corner,
70
268597
2920
ืื– ื” 2 ื—ื™ื™ื‘ ืœื”ื™ื•ืช ื‘ืคื™ื ื”,
04:31
and you can then place the upper level like this.
71
271684
3295
ื•ืืชื ื™ื›ื•ืœื™ื ืื– ืœืžืงื ืืช ื”ืจืžื” ื”ืขืœื™ื•ื ื” ื›ืš.
04:35
Youโ€™ve barely snapped the last energy cell into place
72
275855
3712
ื‘ืงื•ืฉื™ ื”ื›ื ืกืชื ืืช ืชื ื”ืื ืจื’ื™ื” ื”ืื—ืจื•ืŸ ืœืžืงื•ื
04:39
when you hear the ringleader announcing your act.
73
279567
2753
ื›ืฉืืชื ืฉื•ืžืขื™ื ืืช ืžื ื”ืœ ื”ื–ื™ืจื” ืžื•ื“ื™ืข ืขืœ ื”ืžื•ืคืข ืฉืœื›ื.
04:42
Youโ€™re pretty sure youโ€™ve also noticed enough clues to solve the mystery.
74
282528
4505
ืืชื ื“ื™ ื‘ื˜ื•ื—ื™ื ืฉื”ื‘ื—ื ืชื ื‘ืžืกืคื™ืง ืจืžื–ื™ื ื›ื“ื™ ืœื–ื”ื•ืช ืืช ื”ืžื—ื‘ืœ.
04:47
Who sabotaged you?
75
287033
1710
ืžื™ ื–ื”?
ืขืœ ืืชืจ ื–ื”

ืืชืจ ื–ื” ื™ืฆื™ื’ ื‘ืคื ื™ื›ื ืกืจื˜ื•ื ื™ YouTube ื”ืžื•ืขื™ืœื™ื ืœืœื™ืžื•ื“ ืื ื’ืœื™ืช. ืชื•ื›ืœื• ืœืจืื•ืช ืฉื™ืขื•ืจื™ ืื ื’ืœื™ืช ื”ืžื•ืขื‘ืจื™ื ืขืœ ื™ื“ื™ ืžื•ืจื™ื ืžื”ืฉื•ืจื” ื”ืจืืฉื•ื ื” ืžืจื—ื‘ื™ ื”ืขื•ืœื. ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ื”ืžื•ืฆื’ื•ืช ื‘ื›ืœ ื“ืฃ ื•ื™ื“ืื• ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ ืžืฉื. ื”ื›ืชื•ื‘ื™ื•ืช ื’ื•ืœืœื•ืช ื‘ืกื ื›ืจื•ืŸ ืขื ื”ืคืขืœืช ื”ื•ื•ื™ื“ืื•. ืื ื™ืฉ ืœืš ื”ืขืจื•ืช ืื• ื‘ืงืฉื•ืช, ืื ื ืฆื•ืจ ืื™ืชื ื• ืงืฉืจ ื‘ืืžืฆืขื•ืช ื˜ื•ืคืก ื™ืฆื™ืจืช ืงืฉืจ ื–ื”.

https://forms.gle/WvT1wiN1qDtmnspy7