beat

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beat

1. Physics the low regular frequency produced by combining two sounds or electrical signals that have similar frequencies
2. Prosody the accent, stress, or ictus in a metrical foot
3. Nautical a course that steers a sailing vessel as close as possible to the direction from which the wind is blowing
4. 
a. the act of scouring for game by beating
b. the organized scouring of a particular woodland so as to rouse the game in it
c. the woodland where game is so roused
5. Fencing a sharp tap with one's blade on an opponent's blade to deflect it

Beat

A variation in the intensity of a composite wave which is formed from two distinct waves with different frequencies. Beats were first observed in sound waves, such as those produced by two tuning forks with different frequencies. Beats also can be produced by other waves. They can occur in the motion of two pendulums of different lengths and have been observed among the different-frequency phonons in a crystal lattice.

One important application of beat phenomena is to use one object with an accurately known frequency to determine the unknown frequency of another such object. The beat-frequency or heterodyne oscillator also operates by producing beats from two frequencies.

beat

[bēt]
(physics)
The periodic variation in amplitude of a wave that is the superposition of two simple harmonic waves of different frequencies.

beat

i. A low-frequency vibration produced when two sources of vibration act on the same object at the same time. For example, in a multiengine airplane, if two engines have slightly different RPM, airframe vibrations produced by these engines will produce a very noticeable beat.
ii. When two waves are combined or superimposed, a beat occurs if two frequencies are not the same. Waves beat together to create the appearance of either a change in amplitude, if the frequencies differ by a few hertz (Hz), or new frequencies, called beat frequencies or heterodynes, if the original frequencies are far apart.
References in periodicals archive ?
The Syrian government forces, backed up by the army artillery units' shelling, continued to beat back Jeish al-Fatah fighters in the two fronts of Housing Project 1070 and military academy building," the sources said.
The Palestinian Authority has been in growing turmoil as Arafat tries to beat back demands for internal reform.
The bill passed 239-182 largely along party lines after Republicans beat back a last-ditch attempt by Democrats to scuttle it.
But Mickelson didn't actually have to beat back a challenge from Woods.
Passengers shrieked as the crew forced the door open and beat back the fire with an extinguisher.
For Villaraigosa to beat back these special interests - many of them already doing their best to curry his favor after supporting Hahn's campaign - he will need to implement even tougher polices and exercise extreme vigilance within his administration.
Glazier said he is confident that California's congressional delegation and others in Congress will beat back the proposal.
People say graduation is in a month, and they're looking forward to it,'' said Abbott, 18, who beat back leukemia to graduate from Saugus High School today.