if u can keep the angular velocity constant, that's uniform circular motion
and in this time, you wanna keep w constant but not v ar ma?
係一個高速盤中, 個w 係keep constant in every point
if w = constant , then F=mrw^2 = kr
if v = constant, then F= mv^2/r = k'/r 原帖由 adamsteve 於 22-11-2008 23:43 發表 http://www1.nakuz.com/bbs/images/common/back.gif
正如yu神所講w 點會係constant 呢 v(magn ...
唔見佢有咁講
原帖由 Zend 於 22-11-2008 23:47 發表 http://www1.nakuz.com/bbs/images/common/back.gif
different stuff bor
if u can keep the angular velocity constant, that's uniform circular motion
and in this time, you wanna keep w constant but not v ar ma?
係一個高速盤中, 個w 係keep constant i ...
我提議佢睇番angular velocity的定義 ω = θ / t 我無直接講出黎,不過唔可以話我無咁既意思.
instantaneous response =/= steady state response.
there are 2 processes in the whole picture.
if w = constant , then F=mrw^2 = kr
if v = constant, then F= mv^2/r = k'/r
both of them are true, but they are not used together in the same process.
[ 本帖最後由 【YU】 於 23-11-2008 01:22 編輯 ] 原帖由 【YU】 於 23-11-2008 01:20 發表 http://www4.nakuz.com/bbs/images/common/back.gif
我無直接講出黎,不過唔可以話我無咁既意思.
instantaneous response =/= steady state response.
there are 2 processes in the whole picture.
both of them are true, but they are not used together...
ic[] 其實ne 樣野new way係有講的~ 原帖由 Zend 於 23-11-2008 12:54 發表 http://www4.nakuz.com/bbs/images/common/back.gif
其實ne 樣野new way係有講的~ 邊樣野 原帖由 piyopiyo 於 23-11-2008 03:18 PM 發表 http://www4.nakuz.com/bbs/images/common/back.gif
邊樣野
that particular thing 原帖由 Zend 於 23-11-2008 16:53 發表 http://www4.nakuz.com/bbs/images/common/back.gif
that particular thing
u mean Fc directly proportion to r?[] or u mean the illustration of why the man will move away the centre 我記得多數都係用返f=mv^2/r 係inversely proportional
v係constant架 yu神都有問你啦 舊野唔通會無啦啦愈行愈快咩
你地應該都係cut左angular momentum架啦 都好少用angular 野黎計
ω = θ / t <--- 其實 同 ω = v/ r 係無分別ge 都可以拎黎用
你自己都可以試下拎去derive一下
你諗唔通 我諗你都係搞唔清楚個ω 係做緊咩姐 慢慢黎 抽離一下 唔好鑽牛角尖 原帖由 adamsteve 於 26-11-2008 00:57 發表 http://www1.nakuz.com/bbs/images/common/back.gif
我記得多數都係用返f=mv^2/r 係inversely proportional
v係constant架 yu神都有問你啦 舊野唔通會無啦啦愈行愈快咩
你地應該都係cut左angular momentum架啦 都好少用angular 野黎計
ω = θ / t
Consider uniform circular motion (v is constant at a particular r).
Assume friction is always large enough (I don't know the mechanics of skidding).
Assume v is constant for all r (by 19#).
Since ω = v/r
As r increases, ω decreases.
ω = θ/t
v/r = θ/t
θ = k/r
In a particular time interval t, a body travels a larger θ if r is smaller.
Please imagine the picture if I places two bodies of the same mass at different r on the same rotating disc.
Actually do you know what the ω we are talking about??
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