| 释义 |
impetus|ˈɪmpɪtəs|
[a. L. impetus assault, onset, violent impulse, violence, force, vehemence, f. impet-ĕre to rush upon, attack, assail, f. im- (im-1) + petĕre to seek.]
1. The force with which a body moves or maintains its velocity and overcomes resistance; energy of motion; impulse, impulsion.
1656Hobbes Six Less. Wks. 1845 VII. 285 The quantity of the impetus may be equal to the quantity of a time. 1667Phil. Trans. II. 440 The Ball, being by the Impetus it acquired in descending, carried downwards. 1717J. Keill Anim. Œcon. (1738) 62 The Blood..successively receives new impetus's from the Ventricles contracting themselves. 1794Sullivan View Nat. II. 389 What is impetus, or force in a moving body? 1878Huxley Physiogr. 174 Whether the stream..retains sufficient impetus to carry it to our shores.
b. Gunnery. The altitude due to the initial velocity of a projectile, i.e. the space through which it must fall to attain an equal velocity; the force of projection as measured by this.
1807Hutton Course Math. II. 154 Having given the Direction, and the Impetus, or Altitude due to the First Velocity of a Projectile; to determine the Greatest Height to which it will rise. 1828J. M. Spearman Brit. Gunner (ed. 2) 249 The space due to the initial velocity is called the impetus.
2. In reference to immaterial things, as feelings, actions, etc.: Moving force, impulse, stimulus.
1641Compl. conc. Corrupt. & Grievances 2 After that first heate and impetus of reformation..the businesse went on no further. 1649J. H. Motion to Parl. Adv. Learn. 29 To prosecute the hints and impetus of their owne inclinations. 1699N. Marsh in Lett. Lit. Men (Camden) 296 Such juvenile impetuses ought to be repress'd. a1714M. Henry Wks. (1835) I. 120 Struggling with the violent impetus of a particular lust. a1830Hazlitt in Half Hours with Best Authors II. 273 What also gave an unusual impetus to the mind of men at this period was the discovery of the New World. 1872Yeats Growth Comm. 238 Fugitive Huguenots gave a fresh impetus to weaving. |