English-Thai Dictionary
pendulum
N ลูกตุ้ม สิ่ง ที่ แกว่ง ไปมา swing pendant oscillator luk-tum
Webster's 1828 Dictionary
PENDULUM
n.[L. pendulus, pendulum. ] A vibrating body suspended from a fixed point; as the pendulum of a clock. The oscillations of a pendulum depend on gravity, and are always performed in nearly equal times, supposing the length of the pendulum and the gravity to remain the same.
Webster's 1913 Dictionary
PENDULUM
Pen "du *lum, n.; pl. Pendulums. Etym: [NL. , fr. L. pendulus hanging, swinging. See Pendulous. ]
Defn: A body so suspended from a fixed point as to swing freely to and fro by the alternate action of gravity and momentum. It is used to regulate the movements of clockwork and other machinery.
Note: The time of oscillation of a pendulum is independent of the arc of vibration, provided this arc be small. Ballistic pendulum. See under Ballistic. -- Compensation pendulum, a clock pendulum in which the effect of changes of temperature of the length of the rod is so counteracted, usually by the opposite expansion of differene metals, that the distance of the center of oscillation from the center of suspension remains invariable; as, the mercurial compensation pendulum, in which the expansion of the rod is compensated by the opposite expansion of mercury in a jar constituting the bob; the gridiron pendulum, in which compensation is effected by the opposite expansion of sets of rodsof different metals. -- Compound pendulum, an ordinary pendulum; -- so called, as being made up of different parts, and contrasted with simple pendulum. -- Conical or Revolving, pendulum, a weight connected by a rod with a fixed point; and revolving in a horizontal cyrcle about the vertical from that point. -- Pendulum bob, the weight at the lower end of a pendulum. -- Pendulum level, a plumb level. See under Level. -- Pendulum wheel, the balance of a watch. -- Simple or Theoretical, pendulum, an imaginary pendulum having no dimensions except length, and no weight except at the center of oscillation; in other words, a material point suspended by an ideal line.
New American Oxford Dictionary
pendulum
pen du lum |ˈpenjələm, ˈpendyə -ˈpɛnʤələm | ▶noun a weight hung from a fixed point so that it can swing freely backward and forward, esp. a rod with a weight at the end that regulates the mechanism of a clock. • used to refer to the tendency of a situation to oscillate between one extreme and another: the pendulum of fashion. DERIVATIVES pen du lar |-lər |adjective ORIGIN mid 17th cent.: from Latin, neuter (used as a noun ) of pendulus ‘hanging down. ’
Oxford Dictionary
pendulum
pendulum |ˈpɛndjʊləm | ▶noun a weight hung from a fixed point so that it can swing freely, especially a rod with a weight at the end that regulates the mechanism of a clock. • used to refer to the tendency of a situation to oscillate between one extreme and another: the pendulum of fashion. The use of the pendulum for regulating clocks depends on the principle, discovered by Galileo c. 1602, that for small amplitudes the time of oscillation of a pendulum depends only on its length. A freely suspended pendulum resists changes in its plane of oscillation, a fact employed by Jean Foucault in 1851 to demonstrate the earth's rotation. DERIVATIVES pendular adjective ORIGIN mid 17th cent.: from Latin, neuter (used as a noun ) of pendulus ‘hanging down ’.
Sanseido Wisdom Dictionary
pendulum
pen du lum /pén (d )ʒ (ə )ləm |-djʊ -/〖語源は 「ぶら下がる 」〗名詞 C 1 (時計などの )振り子 .2 〖単数形で; 通例the ～〗(意見 流行 政治勢力などの )変化, 動揺 ; 趨勢 （すうせい ）▸ the pendulum of medical opinion 医学的見解の変化 ▸ the swing of the pendulum 振り子の揺れ ; 世論の動き
The Wordsmith Dictionary