推 recorriendo:簡單的說 如果所有物理在同樣重力場中的加速度都一樣 03/18 09:08
→ recorriendo:那麼物體的慣性與重力質量之比是普適常數 可取為1 03/18 09:11
→ recorriendo:有單位的量本來就無所謂等於不等於 只有比例上的關係 03/18 09:12
→ recorriendo:現在測試等校園裡的實驗也是在量不同原子在同一重力場 03/18 09:13
→ recorriendo:中的加速度一不一樣 03/18 09:14
Sorry but I cannot type Chinese.
I have a question.
1. inertial mass: m_i = F/a
2. gravitational mass: m_g = W/g. How do you determine W or g?
(1)
Given an (inertial) mass m_i, we apply a force on it so that the mass
has an acceleration a. By Newton's second law (definition of force),
we know the force F = m_i a.
After knowing the magnitude of F, we can also determine m_i by measuring
the acceleration.
fine.....
(2)
How do we define m_g?
HDT said that we define "1kg" (gravitational) mass first. OK...
W = m_g g ....
m_g is defined...
W is the force, and therefore W = m_i a.
=> m_i a = m_g g.
Everything is fine...
now...go back to (1). What's m_i ? Is it defined first from m_g ?
Of course, it cannot be. Otherwise, m_i = m_g is for sure..
then...how is m_i defined first?
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※ 編輯: chungweitw 來自: 128.227.79.73 (03/16 23:42)