加速度

• Reading: かそくど
• Romaji: kasokudo
• Kanji breakdown: 加 (ka) — to add, to increase; 速 (soku) — speed, velocity; 度 (do) — degree, measure
• Pronunciation: /ka.so.kɯ.do/

Meaning

Acceleration; the rate of change of velocity with respect to time. A fundamental quantity in classical mechanics.

A physics term: 加速 (acceleration, speeding up) + 度 (degree, measure). In Newtonian mechanics, acceleration is defined by Newton's second law: 力 = 質量 × 加速度 (F = ma). The SI unit is metres per second squared (m/s²). In everyday Japanese, 加速度的に is used adverbially to mean 'at an accelerating rate' or 'exponentially' (e.g., 技術は加速度的に進化している — technology is advancing at an accelerating rate). The related term 重力加速度 (gravitational acceleration) is approximately 9.8 m/s².

Examples

1. ニュートンの第二法則によると、力は質量と加速度の積に等しい。 According to Newton's second law, force equals the product of mass and acceleration.
2. 自動車のブレーキをかけると負の加速度、つまり減速が生じる。 When a car's brakes are applied, negative acceleration — that is, deceleration — occurs.
3. AIの能力は加速度的に向上しており、近い将来に劇的な変化をもたらすと予測されている。 AI capabilities are improving at an accelerating rate, and it is predicted that dramatic changes will occur in the near future.

Usage Guide

Context: physics, engineering, mechanics, automotive, academic writing

Tone: technical, neutral

Origin & History

Meiji-era Sino-Japanese coinage: 加速 (kasoku) — acceleration + 度 (do) — degree, measure. 加速 itself combines 加 (to add, to increase) and 速 (speed, velocity). Coined to render Newton's concept of 'acceleration' in Japanese physics education.

Cultural Context

Era: Meiji-Modern

Generation: Adult

Social background: Educated