推 leepei:為何我算出來的數字都相當醜陋...... 02/12 23:50
推 s636220:我算出來也很醜 02/13 00:15
推 s636220:我算是V= 4.14 W= 4.87 繩長9米 02/13 01:05
※ 編輯: s636220 來自: 61.231.98.22 (02/13 13:39)
※ 引述《s636220 (s636220)》之銘：
: a solid uniform disk of mass 21 kg and radius 0.85m is at rest flat on a
: fractionless surface . A string is wrapping around the rim of disk and a
: constant force of 30N is applied to the string .The string dose not slip on
: the rim .(Icm for disk is 1/2MR^2) when the disk has moved a distance 9m
: 1.how fast is it moving?
: (A)2.6m/s(B)5.1m/s(c)10.1m/s(d)20.4m/s(e)none of the above
: 2.how fast is it spinning?
: (a)3.0rad/s(b)6.2rad/s(c)11.9rad/s(d)20.4rad/s(e)none of the above
: 3.how much string(length) has unwrapped from around the rim?
: (a)4.5m(b)9m(c)18m(d)36m(e)none of the above
一個圓盤質量 21 kg 半徑 0.85m 放在一個光滑無摩擦的平面上
有一條繩子繞在圓盤的周圍 且提供30N 的定力 (繩子和圓盤間不滑動)
(圓盤繞圓心旋轉的轉動慣量 1/2MR^2)
當圓盤移動 9 m 時 求此時
(1) 移動速度
(2) 角速度
(3) 繩子拉了多長
圖大概是這樣
_____________________
___30N ____ │
│○ ○ │
│ → 9m │無摩擦平面
____________________│
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