惯量 (guàn liàng) — moment of inertia (physics)

Definition

Physics term: the moment of inertia of an object, a measure of its resistance to changes in rotation that depends on its mass distribution.

noun

moment of inertia (physics)

惯量。
Zhè ge wù tǐ de guàn liàng hěn dà.
This object has a large moment of inertia.
惯量。
Jì suàn guàn liàng xū yào zhī dào zhì liàng hé xíng zhuàng.
Calculating moment of inertia requires knowing mass and shape.
惯量。
Gōng chéng shī fēn xī le jī qì de guàn liàng.
The engineer analyzed the machine's moment of inertia.

Compound word

构词法gòucífǎ

偏正piānzhèngModifier + head

The first part narrows down the second: it says what kind of thing the head is.

惯 points to inertia and 量 to quantity, naming a physical measure.

Characters in this word

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 慣; 惯 is its simplified writing.

忄貫慣

Meaning part形符xíngfú

忄Written in full as心xīnheart

Sound part声符shēngfú

貫

貫guàn慣guàn

Same sound today

The traditional form 慣 shows 忄 (heart) beside 貫, which gives the sound; the simplified 惯 is a shorthand. Habit is what one does by heart.

Two or more meaningful parts placed together so that their meanings combine into a new one.

量 has 日 (sun) over 東 (bag; east). Some explanations suggest measuring under the sun or the sun rising in the east, but the exact origin is unclear.