【化】 冲击摆

[ noun ]
a physical pendulum consisting of a large mass suspended from a rod; when it is struck by a projectile its displacement is used to measure the projectile's velocity
<noun.artifact>

Pendulum \Pen"du*lum\, n.; pl. {Pendulums}. [NL., fr. L.
pendulus hanging, swinging. See {Pendulous}.]
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 pendulum} 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 pendulum} 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.


Ballistic \Bal*lis"tic\, a.
1. Of or pertaining to the ballista, or to the art of hurling
stones or missile weapons by means of an engine.

2. Pertaining to ballistics[2], or to a projectile in a
gravitational field.
[1913 Webster +PJC]

3. frenzied; very angry; -- used mostly in the phrase

{go ballistic}. [Colloq.]
[PJC]

{Ballistic pendulum}, an instrument consisting of a mass of
wood or other material suspended as a pendulum, for
measuring the force and velocity of projectiles by means
of the arc through which their impact impels it.