Im-sok

Im-sok (音速), iū hō-chò siaⁿ-sok (聲速), chiū sī siaⁿ-im ê sok-tō͘, tēng-gī chò tan-ūi sî-kan lāi chín-tōng pho thoân-tē ê kī-lī. Im-sok hām thoân-tē kài-chit ê châi-chit chōng-hóng, chhin-chhiūⁿ bi̍t-tō͘, un-tō͘ kap ap-le̍k téng-téng, ū choa̍t-tùi ê koan-hē; tian-tó hām hoat-siaⁿ pho-goân pún-sin ê sok-tō͘ bô-koan. Nā-sī hoat-siaⁿ kap thiaⁿ-siaⁿ ê lâng chi-kan ū siong-tùi ūn-tōng ê koan-hē, chiū ē hêng-sêng Doppler hāu-èng. Ùi chit-ê koan-tiám chhut-hoat, lán ē-tàng chai-iáⁿ, chhiau-im-sok sî ê chē-chē bu̍t-lí hiān-siōng, chhin-chhiūⁿ chhiong-kek-pho kap im-po̍k, kî-si̍t hām siaⁿ-im bô-koan, sī hām ap-sok-pho bi̍t-chi̍p lúi-chek só͘ sán-seng ê bu̍t-lí hiān-siōng. Siaⁿ-im ê thoân-pò͘ sok-tō͘ tī kò͘-thé siōng-kín, tē-jī sī e̍k-thé, ah khì-thé ê im-sok siōng-kài bān. Thong-siông ê "im-sok" sī teh kóng khong-khì tiong ê im-sok, sī 343.2 m/s (1,236 km/hr). Im-sok ê kín-bān koh ē chiàu khong-khì ê chōng-thài, chhin-chhiūⁿ sip-tō͘, un-tō͘, bi̍t-tō͘ téng-téng, ê bô-kāng ū bô-kāng ê sò͘-ti̍t.