1
00:00:01,611 --> 00:00:03,798
<b>上面写着KN 千牛顿</b>

2
00:00:04,863 --> 00:00:12,738
<b>看完这段视频 你会比其他99%的攀岩者有更好的理解</b>

3
00:00:12,988 --> 00:00:15,488
<b>KN 到底意味着什么意思</b>

4
00:00:16,071 --> 00:00:19,946
<b>以及攀爬冲坠过程中所涉及的力是哪些</b>

5
00:00:20,488 --> 00:00:27,155
<b>然后我会解释为什么大距离的坠落比小距离的坠落要柔和得多</b>

6
00:00:27,155 --> 00:00:30,155
<b>但首先 让我们看看力是什么</b>

7
00:00:30,155 --> 00:00:32,723
<b>我喜欢和我的Instagram粉丝一起互动</b>

8
00:00:32,723 --> 00:00:34,571
<b>所以我决定问问他们</b>

9
00:00:34,571 --> 00:00:38,780
<b>当他们听到“力”这个词时 他们会想到什么</b>

10
00:00:38,780 --> 00:00:42,571
<b>一半的人说这和《星球大战》 有关</b>

11
00:00:43,488 --> 00:00:44,321
<b>很好</b>

12
00:00:44,655 --> 00:00:50,530
<b>在你觉得我Instagram上一半的粉丝都很聪明之前</b>

13
00:00:50,655 --> 00:00:53,780
<b>我不得不说 大多数人根本没有投票</b>

14
00:00:53,895 --> 00:00:55,561
<b>所以我想象大家可能是这个状态</b>

15
00:00:55,821 --> 00:00:58,196
<b>力指的是什么</b>

16
00:01:00,738 --> 00:01:03,821
<b>好的 那些聪明的人说 </b>

17
00:01:03,821 --> 00:01:07,155
*<i>力 是 质量</i> 加速度 **

18
00:01:07,155 --> 00:01:09,238
<b> 这是牛顿第二运动定律</b>

19
00:01:09,280 --> 00:01:11,446
<b>这个人提出了这个定律 </b>

20
00:01:11,446 --> 00:01:14,446
<b>这就是为什么我们用牛顿这个单位来测量力</b>

21
00:01:14,446 --> 00:01:17,113
<b>当你思考它的时候 </b>

22
00:01:17,238 --> 00:01:18,905
<b>想象一下牛顿</b>

23
00:01:22,446 --> 00:01:24,905
<b>所以我们用kg 作为质量单位</b>

24
00:01:28,613 --> 00:01:33,155
<b>加速度 以m/s²为单位</b>

25
00:01:35,613 --> 00:01:40,280
<b>力以n（牛顿）来做单位</b>

26
00:01:42,988 --> 00:01:48,071
<b>为了更好地理解这个公式 它就像1牛顿 </b>

27
00:01:48,946 --> 00:01:51,738
<b>推动一千克的质量</b>

28
00:01:52,280 --> 00:01:58,905
<b>使质量的加速度是1m/s²</b>

29
00:01:58,905 --> 00:02:00,738
<b>这里有一个锁扣</b>

30
00:02:01,696 --> 00:02:04,780
<b>如果我把全身重量都压在上面 </b>

31
00:02:05,113 --> 00:02:06,488
<b>像这样</b>

32
00:02:06,488 --> 00:02:10,155
<b>问题是 现在这个锁扣的力是多少</b>

33
00:02:10,155 --> 00:02:12,363
<b>如果我们回头看这个公式 </b>

34
00:02:12,613 --> 00:02:15,613
<b>我们可以说 m 就是我的质量</b>

35
00:02:15,988 --> 00:02:18,446
<b>乘以加速度 </b>

36
00:02:19,780 --> 00:02:23,905
<b>加速度是多少 我挂在树上 没有运动 没有加速度</b>

37
00:02:25,113 --> 00:02:27,238
<b>或者有一个加速度</b>

38
00:02:30,155 --> 00:02:33,613
<b>你们可能见过这个实验 </b>

39
00:02:33,780 --> 00:02:36,780
<b>有一个轻的物体和一个重的物体</b>

40
00:02:37,488 --> 00:02:41,405
<b>问题是 如果我同时放开它们 </b>

41
00:02:41,738 --> 00:02:44,155
<b>哪个会先着地</b>

42
00:02:44,780 --> 00:02:45,863
<b>让我们试一试</b>

43
00:02:55,946 --> 00:02:58,571
<b>所以是的 它们同时下落到地面 </b>

44
00:02:58,696 --> 00:03:01,946
<b>因为重力就是这样 它让物体下落</b>

45
00:03:02,238 --> 00:03:07,363
<b>以同样的加速度 9.8m/s²</b>

46
00:03:15,905 --> 00:03:18,030
<b>所以当我挂在锁链上的时候</b>

47
00:03:18,613 --> 00:03:20,113
<b>地心引力把我往下拉</b>

48
00:03:20,488 --> 00:03:23,196
<b>但是为了让我不向下移动 </b>

49
00:03:23,196 --> 00:03:25,530
<b>一定有一个相反的力 </b>

50
00:03:25,530 --> 00:03:27,280
<b>把我拉上来 </b>

51
00:03:27,488 --> 00:03:28,905
<b>这里我有一个弹簧</b>

52
00:03:29,530 --> 00:03:32,738
<b>当重力将岩石向下拉时 </b>

53
00:03:32,738 --> 00:03:35,238
<b>弹簧将岩石向上拉</b>

54
00:03:35,571 --> 00:03:39,196
<b>这个锁扣实际上就像一个非常非常硬的弹簧</b>

55
00:03:39,363 --> 00:03:40,821
<b>它把我拉上来</b>

56
00:03:41,196 --> 00:03:44,238
<b>当我挂在锁扣上时 </b>

57
00:03:44,238 --> 00:03:46,155
<b>锁扣的分子会趋于分散</b>

58
00:03:46,196 --> 00:03:49,946
<b>原本分子聚集的力量会产生类似拉的作用 </b>

59
00:03:49,946 --> 00:03:53,821
<b>这种在低拉力下的扩张你是看不到的</b>

60
00:03:54,280 --> 00:03:55,821
<b>但是大的力就可以</b>

61
00:04:02,280 --> 00:04:07,405
<b>结果是这个锁扣举起了我的体重</b>

62
00:04:08,071 --> 00:04:12,780
<b>以同样的9.8m/s²的加速度 </b>

63
00:04:12,780 --> 00:04:15,780
<b>也就是大约600N</b>

64
00:04:16,321 --> 00:04:18,655
<b>是啊 六百个这样的东西</b>

65
00:04:18,655 --> 00:04:22,113
<b>才能拉住我这样的瘦子 </b>

66
00:04:28,780 --> 00:04:30,363
<b>好了 我们继续</b>

67
00:04:30,821 --> 00:04:36,530
<b>这个主锁显示它能承受26kn的重量</b>

68
00:04:37,571 --> 00:04:41,030
<b>KN等于一千牛顿</b>

69
00:04:41,030 --> 00:04:46,446
<b>所以这意味着它能承载40个我</b>

70
00:04:46,446 --> 00:04:48,863
<b>我希望我有一台克隆机器</b>

71
00:04:48,863 --> 00:04:51,280
<b>这样我就可以向你们展示这个</b>

72
00:04:52,613 --> 00:04:58,446
<b>然后想象一下我能制作多少视频</b>

73
00:05:01,196 --> 00:05:03,405
<b>如果你想见我们</b>

74
00:05:03,696 --> 00:05:05,905
<b>创建更多像这样的视频 </b>

75
00:05:05,905 --> 00:05:08,905
<b>点击点赞和关注按钮 它确实有帮助</b>

76
00:05:09,196 --> 00:05:10,196
<b>我保证 </b>

77
00:05:10,196 --> 00:05:15,946
<b>我会把从你们那里得到的每一分钱都花在买克隆机器上</b>

78
00:05:18,738 --> 00:05:24,280
<b>好吧 你可以用一个锁扣挂40个我</b>

79
00:05:24,905 --> 00:05:26,030
<b>这很厉害</b>

80
00:05:26,821 --> 00:05:29,530
<b>虽然有些事情你必须知道 </b>

81
00:05:29,530 --> 00:05:33,738
<b>首先 这些负荷参数是针对新装备的</b>

82
00:05:34,113 --> 00:05:36,905
<b>磨损不包括在这个评级之内</b>

83
00:05:37,613 --> 00:05:38,905
<b>这有多糟糕</b>

84
00:05:39,238 --> 00:05:44,196
<b>我问了我在油管HowNOTtoHighline频道的朋友Ryan</b>

85
00:05:44,196 --> 00:05:47,405
<b>因为他有破坏东西的爱好</b>

86
00:05:47,988 --> 00:05:49,780
<b>根据他的测试</b>

87
00:05:50,113 --> 00:05:53,321
<b>大多数金属都很耐用</b>

88
00:05:53,488 --> 00:05:55,738
<b>而软性材料的东西</b>

89
00:05:56,071 --> 00:05:58,696
<b>完全不同</b>

90
00:05:59,071 --> 00:06:02,655
<b>[Ryan] BD的 22KN 扁带</b>

91
00:06:09,071 --> 00:06:09,363
<b>什么</b>

92
00:06:10,655 --> 00:06:13,280
<b>MBS是多少 22kn吗</b>

93
00:06:13,321 --> 00:06:17,321
<b>是的 一个性能为22kn的扁带</b>

94
00:06:17,321 --> 00:06:18,946
<b>在6kn左右就断了</b>

95
00:06:19,863 --> 00:06:21,280
<b>接下来是另一个例子</b>

96
00:06:22,280 --> 00:06:24,821
<b>[Ryan] 这是另一个状态很好的扁带</b>

97
00:06:24,821 --> 00:06:26,988
<b> 没拉扯过</b>

98
00:06:27,655 --> 00:06:28,905
<b>[Ryan] 对 没拉扯过</b>

99
00:06:30,321 --> 00:06:31,780
<b>我会把我的狗拴在上面</b>

100
00:06:38,196 --> 00:06:39,821
<b>我可不会把一条大狗拴在上面 </b>

101
00:06:43,363 --> 00:06:47,113
<b>让我们看看你能用这个牵住多大的狗</b>

102
00:06:48,071 --> 00:06:49,738
<b>哦 一个吉娃娃吗?</b>

103
00:06:50,696 --> 00:06:54,571
<b>是的 所以如果你是那种喜欢省钱的人 </b>

104
00:06:54,571 --> 00:06:57,571
<b>用着很旧的且磨损的扁带</b>

105
00:06:58,280 --> 00:06:58,780
<b>祝你好运</b>

106
00:06:58,905 --> 00:06:59,613
<b>24kn</b>

107
00:07:04,363 --> 00:07:05,655
<b>这并没有延伸太多 </b>

108
00:07:05,655 --> 00:07:08,655
<b> 哦 猜猜猜</b>

109
00:07:08,655 --> 00:07:09,488
<b>你猜怎么着?</b>

110
00:07:09,488 --> 00:07:11,155
<b>[Ryan] 4kn</b>

111
00:07:11,155 --> 00:07:13,155
<b>搞什么鬼 伙计 </b>

112
00:07:13,155 --> 00:07:18,821
<b>4kn 那这个扁带能承受多少</b>

113
00:07:19,446 --> 00:07:23,738
<b>这很简单 只要用4000除以9.8</b>

114
00:07:24,488 --> 00:07:26,863
<b>如果你想简单一点 除10代替 </b>

115
00:07:26,863 --> 00:07:29,155
<b>你得到400公斤 </b>

116
00:07:29,863 --> 00:07:32,655
<b>这听起来很多</b>

117
00:07:34,071 --> 00:07:34,863
<b>好吧</b>

118
00:07:35,946 --> 00:07:40,696
<b>所有这些都是我一直在讲的从力到千克的换算</b>

119
00:07:41,321 --> 00:07:45,488
<b>都是基于重量是静止的这个事实 </b>

120
00:07:45,488 --> 00:07:49,196
<b>一旦物体开始下落 一切都会改变</b>

121
00:07:53,905 --> 00:07:56,780
<b>你们刚才看到的是DMM的一段视频 </b>

122
00:07:56,780 --> 00:07:59,780
<b>他们扔下了80公斤的重物</b>

123
00:07:59,780 --> 00:08:02,780
<b>破坏了一个全新的Dyneema扁带</b>

124
00:08:03,613 --> 00:08:05,655
<b>我的目的不是吓唬你 </b>

125
00:08:05,655 --> 00:08:07,155
<b>恰恰相反 </b>

126
00:08:07,155 --> 00:08:10,780
<b>我想让大家意识到 攀岩装备并不是魔法</b>

127
00:08:10,988 --> 00:08:14,238
<b>如果你使用错误 它可能会失效</b>

128
00:08:16,780 --> 00:08:17,905
<b>事实上 </b>

129
00:08:17,905 --> 00:08:19,696
<b>你知道岩友在攀爬失败时</b>

130
00:08:19,696 --> 00:08:21,696
<b>喜欢说的这个笑话吗?</b>

131
00:08:21,905 --> 00:08:24,196
<b>今天的引力有点大</b>

132
00:08:24,905 --> 00:08:26,738
<b>事实证明这是真的</b>

133
00:08:27,113 --> 00:08:29,863
<b> 重力确实每个月都在变化</b>

134
00:08:30,280 --> 00:08:30,655
<b>所以</b>

135
00:08:30,863 --> 00:08:35,905
<b>如果你是那种喜欢抱怨今天湿度</b>

136
00:08:35,905 --> 00:08:37,196
<b>或温度不好的人</b>

137
00:08:37,196 --> 00:08:40,988
<b>现在你有权利抱怨今天是糟糕的重力日</b>

138
00:08:41,863 --> 00:08:47,821
<b>好了 让我们看看当物体开始下落时会发生什么 </b>

139
00:08:51,113 --> 00:08:53,321
<b>这是一个10米长度的下落</b>

140
00:08:54,196 --> 00:08:57,530
<b>让我们看看这样的下落会给攀登者带来多大的力</b>

141
00:08:58,113 --> 00:09:01,780
<b>它的公式和之前的差不多 </b>

142
00:09:01,780 --> 00:09:03,905
<b>除了需要乘以这个</b>

143
00:09:04,238 --> 00:09:06,780
<b>攀爬者下落的距离</b>

144
00:09:07,071 --> 00:09:11,030
<b>然后除以攀爬者减速的距离</b>

145
00:09:16,905 --> 00:09:18,571
<b>你有没有注意到 </b>

146
00:09:18,571 --> 00:09:21,113
<b>攀爬者落下时的冲击力相对比较软</b>

147
00:09:23,280 --> 00:09:26,071
<b>所以想象一下在高速公路上开车 </b>

148
00:09:26,613 --> 00:09:31,030
<b>通过轻轻地踩下刹车去停车</b>

149
00:09:31,571 --> 00:09:32,655
<b>没有问题对吧</b>

150
00:09:33,030 --> 00:09:35,280
<b>现在想象你没有开那么快</b>

151
00:09:35,280 --> 00:09:37,655
<b>你在一个城市里 你开得很慢 </b>

152
00:09:37,655 --> 00:09:39,196
<b>但是你撞上了一座桥</b>

153
00:09:40,280 --> 00:09:43,363
<b>感觉不太好 对吧?</b>

154
00:09:43,571 --> 00:09:46,821
<b>这是我想让你们记住的第一件事</b>

155
00:09:47,238 --> 00:09:49,905
<b>对攀登者的冲击</b>

156
00:09:49,905 --> 00:09:56,738
<b>永远是攀登者下落的距离除以下落面距离</b>

157
00:09:57,530 --> 00:09:59,196
<b>让我们计算一下</b>

158
00:09:59,196 --> 00:10:02,196
<b>下落的距离大约是4个快挂 </b>

159
00:10:02,405 --> 00:10:05,905
<b>而下降的距离大约是2个半快挂</b>

160
00:10:06,571 --> 00:10:09,571
<b>我们得到大约860牛顿</b>

161
00:10:09,571 --> 00:10:13,821
<b>或者如果我们用这个标准的80公斤的攀爬者来代替</b>

162
00:10:13,821 --> 00:10:17,655
<b>大约是1.3kn</b>

163
00:10:18,571 --> 00:10:19,488
<b>这并不多</b>

164
00:10:20,155 --> 00:10:22,530
<b>尽管这个公式有一个小问题 </b>

165
00:10:22,530 --> 00:10:28,446
<b>因为它总是会给你一个值 比实际值略低</b>

166
00:10:28,905 --> 00:10:31,821
<b>但是展示更精确地计算 </b>

167
00:10:31,821 --> 00:10:35,738
<b>这意味着你们中的大多数人可能会离开这个视频</b>

168
00:10:36,071 --> 00:10:37,905
<b>但我们不需要这样做</b>

169
00:10:37,905 --> 00:10:41,613
<b>因为我们可以依靠现实生活中的实验数据</b>

170
00:10:41,863 --> 00:10:45,030
<b>谁为我们提供这些数据</b>

171
00:10:45,280 --> 00:10:46,738
<b>大家好 我是Ryan Jenks </b>

172
00:10:46,738 --> 00:10:49,071
<b>广告已经足够了</b>

173
00:10:49,363 --> 00:10:50,780
<b>在这个视频中 </b>

174
00:10:50,780 --> 00:10:54,196
<b>他们放了一个设备来测量攀爬者所受的力</b>

175
00:10:54,196 --> 00:10:56,488
<b>然后做了一系列的冲坠</b>

176
00:11:07,280 --> 00:11:09,113
<b>为了科学</b>

177
00:11:13,988 --> 00:11:15,821
<b>1.87kn的力</b>

178
00:11:16,113 --> 00:11:17,238
<b>所以在我看来</b>

179
00:11:17,238 --> 00:11:20,238
<b>大部分的冲坠都是一个很好的保护案例</b>

180
00:11:20,488 --> 00:11:22,571
<b>低于2kn</b>

181
00:11:22,571 --> 00:11:26,071
<b>现在我们来看看这两个极端的例子</b>

182
00:11:26,571 --> 00:11:29,571
<b>左边的攀登者在挂片上方5米 </b>

183
00:11:29,571 --> 00:11:31,863
<b>所以会有10米长的冲坠</b>

184
00:11:31,988 --> 00:11:34,113
<b>加上绳索的延展性</b>

185
00:11:34,113 --> 00:11:37,071
<b>保护者可能有一米的余量</b>

186
00:11:37,071 --> 00:11:41,405
<b>然后在快挂之间可能还有一米的余量</b>

187
00:11:41,696 --> 00:11:44,655
<b>所以总的来说 我们将看到12米的坠落</b>

188
00:11:44,988 --> 00:11:48,280
<b>而右边的攀爬距离挂片只有一米</b>

189
00:11:48,613 --> 00:11:51,405
<b>假设保护员非常害怕</b>

190
00:11:51,405 --> 00:11:54,530
<b>他要硬生生地接住攀爬者 并没什么缓冲</b>

191
00:11:54,780 --> 00:11:56,821
<b>我们看到的是两米高的坠落</b>

192
00:11:58,155 --> 00:12:01,030
<b>所以从12米高的地方摔下来 </b>

193
00:12:01,030 --> 00:12:02,946
<b>还是从2米高的地方摔下来 </b>

194
00:12:03,155 --> 00:12:06,238
<b>你觉得哪个对攀岩者来说比较软</b>

195
00:12:06,488 --> 00:12:09,905
<b>让我们看一下 我们已经知道了会掉下来多少</b>

196
00:12:09,905 --> 00:12:14,530
<b> 但现在我们需要找出两种情况下的减速距离</b>

197
00:12:14,988 --> 00:12:17,280
<b>这主要取决于两个因素</b>

198
00:12:17,571 --> 00:12:20,363
<b>首先是保护者的位移</b>

199
00:12:20,738 --> 00:12:22,071
<b>一个非常非常大的冲坠 </b>

200
00:12:22,071 --> 00:12:25,071
<b>保护员大概会飞两米左右</b>

201
00:12:26,280 --> 00:12:27,280
<b>在小的冲坠时 </b>

202
00:12:27,280 --> 00:12:30,280
<b> 让我们假设 对于初学者来说有非常常见的错误</b>

203
00:12:30,280 --> 00:12:34,030
<b>保护员只是收紧绳子和反应迟钝</b>

204
00:12:34,488 --> 00:12:37,738
<b>第二个因素是绳子的伸展性</b>

205
00:12:38,238 --> 00:12:40,155
<b>绳子制造商声称 </b>

206
00:12:40,155 --> 00:12:43,488
<b>如果你把80公斤的质量放在一根动力绳子上</b>

207
00:12:43,821 --> 00:12:46,613
<b>像这样静止不动</b>

208
00:12:47,030 --> 00:12:49,280
<b>绳子会伸长10%</b>

209
00:12:49,280 --> 00:12:52,280
<b>当你先锋状态下冲坠 动态拉伸将会 </b>

210
00:12:52,530 --> 00:12:54,696
<b>高达30%</b>

211
00:12:55,488 --> 00:12:58,655
<b>嗯 高达30%对我们来说不是很有帮助</b>

212
00:12:58,655 --> 00:13:01,780
<b>我们需要知道的是绳子</b>

213
00:13:02,363 --> 00:13:06,321
<b>从2到4千牛顿的拉力时的变化</b>

214
00:13:06,863 --> 00:13:09,280
<b>再一次 我给Ryan发了消息</b>

215
00:13:09,280 --> 00:13:12,988
<b>所以我要拉一根动态绳子 看看它拉伸了多少</b>

216
00:13:12,988 --> 00:13:14,863
<b>一开始 我们以为会很简单</b>

217
00:13:14,863 --> 00:13:16,113
<b>去公园就行</b>

218
00:13:16,113 --> 00:13:18,321
<b>用不同的力拉伸绳子</b>

219
00:13:18,405 --> 00:13:20,613
<b> 测量绳子的伸长</b>

220
00:13:21,155 --> 00:13:24,821
<b>好吧 有时候简单是困难的</b>

221
00:13:25,155 --> 00:13:28,738
<b> 然后你把绳子拉到一定的力 然后把它留在那里</b>

222
00:13:29,071 --> 00:13:31,280
<b>力开始落在绳子上</b>

223
00:13:31,571 --> 00:13:33,113
<b>绳子就这么断了</b>

224
00:13:33,571 --> 00:13:36,863
<b>虽然这很有趣 但对我们来说并不致命</b>

225
00:13:36,863 --> 00:13:39,321
<b>他需要做的唯一一件事</b>

226
00:13:39,321 --> 00:13:42,321
<b>就是以他所希望的力尽可能快地拉绳子</b>

227
00:13:42,488 --> 00:13:44,488
<b>然后测量拉伸程度</b>

228
00:13:46,113 --> 00:13:48,071
<b>天啊 那是七米标志</b>

229
00:13:49,738 --> 00:13:52,196
<b>6.9米 </b>

230
00:13:53,155 --> 00:13:59,530
<b>这是4kn情况下动力绳的伸展长度</b>

231
00:13:59,530 --> 00:14:01,571
<b>但还有另一个有趣的因素 </b>

232
00:14:01,571 --> 00:14:04,196
<b>一旦你给绳子施加大的力</b>

233
00:14:04,446 --> 00:14:08,363
<b>绳子需要一段时间才能恢复到原来的长度 </b>

234
00:14:08,613 --> 00:14:11,113
<b>这就是所谓的绳索休息</b>

235
00:14:11,571 --> 00:14:13,863
<b>看这些变化真的很酷</b>

236
00:14:13,863 --> 00:14:17,030
<b>看到龟龟慢慢被拉回来了吗?</b>

237
00:14:19,780 --> 00:14:21,113
<b>超级有趣</b>

238
00:14:22,238 --> 00:14:24,780
<b>也许我现在比你更感兴趣</b>

239
00:14:25,363 --> 00:14:28,863
<b>他在公园里拉了四个小时的绳子</b>

240
00:14:29,238 --> 00:14:33,738
<b>结果是在2到4kn的力作用下</b>

241
00:14:33,946 --> 00:14:37,363
<b>绳子拉伸到大约20%</b>

242
00:14:37,905 --> 00:14:40,821
<b>很好 我们把它用到计算中</b>

243
00:14:41,155 --> 00:14:45,238
<b>在一个大的下落过程中 我们总共有27米的绳子 </b>

244
00:14:45,238 --> 00:14:49,280
<b>所以这将是5.4米的拉伸</b>

245
00:14:49,696 --> 00:14:52,738
<b>在一个小的下落过程中 我们有5米长的绳子 </b>

246
00:14:52,738 --> 00:14:54,988
<b>那就是1米的拉伸</b>

247
00:14:55,196 --> 00:14:58,363
<b>然而 我们的保护员却惊慌失措 奋力挣扎</b>

248
00:14:58,738 --> 00:15:05,613
<b>所以他会自己留半米 给攀登者留下半米</b>

249
00:15:06,655 --> 00:15:09,821
<b>对于攀岩者来说 长距离的冲坠 </b>

250
00:15:09,821 --> 00:15:15,280
<b>比小的冲坠要软2.5倍</b>

251
00:15:16,446 --> 00:15:19,071
<b>我喜欢有趣的事实 这是另一个 </b>

252
00:15:19,183 --> 00:15:21,350
<b>想象一下你没有完攀</b>

253
00:15:21,846 --> 00:15:27,388
<b>但是那天的湿度 温度 甚至重力都很好</b>

254
00:15:28,446 --> 00:15:30,613
<b>你仍然可以责怪月亮</b>

255
00:15:30,613 --> 00:15:32,571
<b>[旁白]可以忽略不计 但确实</b>

256
00:15:33,223 --> 00:15:38,556
<b>当月亮正对着你时 你的体重会减少一百万分之一</b>

257
00:15:38,821 --> 00:15:42,863
<b>所以 如果你想在月亮正对着你的时候完成线路</b>

258
00:15:43,530 --> 00:15:45,155
<b>那加油</b>

259
00:15:45,571 --> 00:15:50,071
<b>我记得当时我在攀爬一条35米长的路线</b>

260
00:15:50,321 --> 00:15:53,113
<b>这是我第一次成功地把所有的动作连接起来</b>

261
00:15:53,280 --> 00:15:54,821
<b>到达顶部锚点时</b>

262
00:15:55,030 --> 00:15:58,696
<b>当我把绳子拉上来准备放入绳子的时候</b>

263
00:15:58,696 --> 00:16:01,280
<b>我的保护员看不清楚我</b>

264
00:16:01,280 --> 00:16:03,238
<b>所以他就给了我很大的绳子余量</b>

265
00:16:03,265 --> 00:16:09,431
<b>最重要的是 倒数那把挂片在很下面的位置</b>

266
00:16:10,201 --> 00:16:15,160
<b>所以当我把绳子往上拉的时候 我失去了平衡 摔了下去</b>

267
00:16:15,821 --> 00:16:18,905
<b>墙在我面前飞舞 </b>

268
00:16:18,905 --> 00:16:21,905
<b>我在想为什么我还在下落 嗯 这很不寻常</b>

269
00:16:21,946 --> 00:16:23,780
<b>然后我停下来 抬头看了看</b>

270
00:16:23,780 --> 00:16:26,155
<b>我上方大概有五六把快挂 </b>

271
00:16:26,155 --> 00:16:29,071
<b>大概有十五米的坠落</b>

272
00:16:29,535 --> 00:16:32,535
<b>但是下落的过程非常柔软 </b>

273
00:16:32,575 --> 00:16:34,158
<b>就像坐电梯一样 </b>

274
00:16:34,366 --> 00:16:36,575
<b>这是这个视频的另一个要点 </b>

275
00:16:36,848 --> 00:16:38,932
<b>如果攀爬者在很高的位置</b>

276
00:16:39,170 --> 00:16:41,586
<b>他有很多绳子来承受坠落 </b>

277
00:16:41,696 --> 00:16:44,696
<b>只要他不掉到什么东西上</b>

278
00:16:44,940 --> 00:16:48,440
<b>无论你如何保护 摔下去的时候会很轻</b>

279
00:16:49,221 --> 00:16:51,821
<b>然而 如果高度不那么高</b>

280
00:16:52,030 --> 00:16:54,780
<b>他没有那么多的绳子来吸收下落</b>

281
00:16:54,780 --> 00:16:58,988
<b>那么一个好的动态缓冲保护是非常重要的</b>

282
00:16:59,696 --> 00:17:02,530
<b>你可以问任何一个轻度攀岩者</b>

283
00:17:02,571 --> 00:17:07,363
<b> 有多少次他们的脚踝因为硬着陆而受伤</b>

284
00:17:07,655 --> 00:17:09,530
<b>好了 让我们换个话题</b>

285
00:17:09,530 --> 00:17:11,363
<b>我们来谈谈摩擦</b>

286
00:17:11,696 --> 00:17:17,030
<b>因为摩擦力越大 对攀登者来说 摔得越重</b>

287
00:17:17,363 --> 00:17:19,696
<b>这有一个非常极端的例子</b>

288
00:17:19,696 --> 00:17:22,696
<b>你们可以看到这里快挂成Z字形</b>

289
00:17:23,780 --> 00:17:27,655
<b>所以当我下落时 会有很大的摩擦力</b>

290
00:17:27,905 --> 00:17:29,071
<b>哇 为了科学</b>

291
00:17:34,280 --> 00:17:39,488
<b>所以摩擦力很大 靠近攀登者的绳子正常伸展</b>

292
00:17:39,738 --> 00:17:42,113
<b>但是保护者附近的绳子 </b>

293
00:17:42,321 --> 00:17:44,030
<b>不会拉伸太多</b>

294
00:17:44,321 --> 00:17:47,488
<b>这就像有是更短的绳子 同时有更重的保护员</b>

295
00:17:47,863 --> 00:17:52,405
<b>让护具承受的力只有2.5kn</b>

296
00:17:52,405 --> 00:17:55,405
<b>许多力像钟摆一样撞在墙上</b>

297
00:17:57,280 --> 00:17:59,363
<b>我们就是这样扭断脚踝的</b>

298
00:17:59,696 --> 00:18:03,071
<b>所以合理的增多快挂</b>

299
00:18:03,071 --> 00:18:05,446
<b>不仅可以帮助你进快挂和避免这种情况</b>

300
00:18:16,655 --> 00:18:20,363
<b>同时也减少了攀爬者承受的冲击力</b>

301
00:18:20,640 --> 00:18:25,306
<b>好 我们回到DMM弄断扁带的测试 </b>

302
00:18:25,613 --> 00:18:29,571
<b>Dyneema扁带是静态的 根本不会拉伸</b>

303
00:18:29,571 --> 00:18:32,988
<b>我希望你们现在已经明白这种突然的停止</b>

304
00:18:32,988 --> 00:18:34,863
<b>可以产生巨大的力</b>

305
00:18:34,988 --> 00:18:37,780
<b>如果没有明白 请别人扇你一巴掌</b>

306
00:18:37,780 --> 00:18:41,946
<b>你需要理解的基本就是在脸上的这个停顿</b>

307
00:18:42,030 --> 00:18:43,863
<b>所以让我们做一个非常大胆的</b>

308
00:18:43,863 --> 00:18:46,155
<b> 可能是一个非常不准确的猜测 </b>

309
00:18:46,155 --> 00:18:50,405
<b>这个扁带会大约延伸到5厘米</b>

310
00:18:51,280 --> 00:18:54,321
<b>所以如果我们放下80千克的质量</b>

311
00:18:54,506 --> 00:18:57,381
<b>扁带长度120厘米</b>

312
00:18:57,907 --> 00:19:01,615
<b>吸收距离只有5厘米 </b>

313
00:19:01,821 --> 00:19:05,196
<b>我们看到的是19kn</b>

314
00:19:06,196 --> 00:19:11,321
<b>如果这都不能把扁带弄断 那肯定会把你弄断</b>

315
00:19:12,821 --> 00:19:14,321
<b>如果你还在看 </b>

316
00:19:14,321 --> 00:19:18,071
<b>这可能意味着你至少应该有点书呆子气 </b>

317
00:19:18,488 --> 00:19:20,405
<b>这是给你的甜点</b>

318
00:19:21,363 --> 00:19:26,905
<b>没有引力 物体不会相互吸引</b>

319
00:19:27,071 --> 00:19:29,030
<b>只有空间和时间</b>

320
00:19:29,030 --> 00:19:31,155
<b>你觉得自己好像被推入了地下</b>

321
00:19:31,946 --> 00:19:33,988
<b>不是因为重力 </b>

322
00:19:34,238 --> 00:19:38,780
<b>而是因为你脑袋上时间比你脚上的时间变化得更快</b>

323
00:19:38,978 --> 00:19:41,533
<b>所以如果你想看到更多类似的内容 </b>

324
00:19:41,585 --> 00:19:44,710
<b>不要忘记订阅并支持我们的频道</b>