equilibrium

均衡、平衡

さまざまな作用がつり合い、全体の状態が変わらないこと。

やさしい英語で： A state in which different effects balance each other, so the overall situation does not change.

• The system reached equilibrium.
• A change in demand disturbed the market's equilibrium.
• The island's animal populations remained in equilibrium for years.

使い方： in equilibrium (Supply and demand are in equilibrium.); equilibrium between A and B (The policy aims for equilibrium between spending and income.)

類義語： balance, stability

反対語： imbalance, disequilibrium

よく使う表現： reach equilibrium, stable equilibrium, market equilibrium

力学的平衡、力のつり合い

物体に働く力がつり合い、速さや進む方向が変わらない状態。

やさしい英語で： A state in which all forces on an object balance, so its speed and direction do not change.

• The object is in equilibrium.
• Equal forces kept the beam in equilibrium.
• A moving object can remain in equilibrium if its velocity stays constant.

使い方： in equilibrium (The hanging weight is in equilibrium.)

類義語： mechanical balance

反対語： disequilibrium

よく使う表現： mechanical equilibrium, static equilibrium, in equilibrium

化学平衡

逆向きの化学反応が同じ速さで起こり、物質の量が変わらない状態。

やさしい英語で： A state where opposite chemical reactions happen equally fast, so the amounts of the substances stay the same.

• The reaction reached equilibrium.
• Heating the mixture changed its chemical equilibrium.
• At equilibrium, the amounts of these chemicals remain constant.

使い方： at equilibrium (At equilibrium, both reactions proceed at the same rate.)

類義語： chemical balance

よく使う表現： chemical equilibrium, equilibrium mixture, reach equilibrium

心の平静、精神的安定

困難な状況でも、心が落ち着いて安定していること。

やさしい英語で： A calm, steady state of mind, even when things are difficult.

• She soon regained her equilibrium.
• A quiet walk helped restore his emotional equilibrium.
• The sudden news disturbed my equilibrium for several days.

類義語： composure, mental balance, calm

よく使う表現： mental equilibrium, emotional equilibrium, regain equilibrium