fill the blanks -10
When a spring or a rubber band is stretched, they tend to regain their original lengths when released, thereby demonstrating ...
elasticity
… is defined as the product of the density of a medium and
sound propagation speed.
impedance
One substance is said to be more elastic than another if it restores its … with greater precision.
original shape
Elasticity is not necessarily correlated with ease of … .
deformation
The deformation of an elastic solid is directly proportional to the deforming force. This linear relationship is called … .
Hooke's law
For a one dimensional motion, Hooke ́s law can be written F=-
kx, where F is … , x is … and k is a numerical proportionality constant.
deforming force ; amount of stretch
The minus sign in the Hook ́s law indicates that the direction of force is opposite to .… .
equivalent point
… motion is defined as a motion which repeats itself at regular
time intervals.
periodic
The frequency of a motion is the number of … completed per
second.
cycles
A mass on a spring has only one natural frequency, determined by the … and the … of the spring according to the
relationship: …
mass ; stiffness ; f = 1/ 2pigreco radice k/m
The unit for frequency is s^-1 and the international name for this frequency unit is … .
Hz
If any part of an elastic medium is disturbed, the disturbance will tend to propagate to all parts of the medium. In all cases, however, the disturbance moves through the medium but the … as a whole does not move.
medium
Waves in which the periodic motion of the particles is … to the
propagation direction are called longitudinal waves.
parallel
If a long coiled spring is stretched at one end, the wave motion will propagate as a series of …. and …. of the spring.
contraction ; expansion
Sound waves in air are … waves because the air molecules
vibrate parallel to the direction of propagation.
longitudinal
An important characteristic of wave motion is that the speed of propagation depends on the … in which the wave is traveling and does not depend upon the ….. sound wave is perceived as a higher … .
medium ; frequency ; amplitude
A higher frequency of a sound wave is perceived as a higher …. .
pitch
The speed of sounds in solids and liquids is considerably higher than the speed in air, but the frequency remains the same since it depends on the …
sound source
The color of light is equivalent to the pitch of sound, in that both are determined by..... .
frequency
Electromagnetic waves with frequencies just below the visible range are donated …. and frequencies just above the visible
range are .…
infraredlight ; ultraviolet
The power per unit area is referred to as the …. of radiation.
intensity
The relationship I=P/4Pir^2 is known as ..… law
inverse square
…. interference occurs where two wave crests coincide and add to produce a larger crest.
constructive
Since the velocity of light is constant, when the wavelength changes, …. must also change.
frequency
The frequencies corresponding to the standing waves are said to be …. frequencies or …. frequencies, similarly to the frequency of a mass on a spring.
natural ; resonant
The Doppler effect for a moving sound source is given by the equation, …. where v is the speed of sound and vs is ..… .
v/ v +- vs ; source speed
Both the sources and the detectors of ultrasound are called .…
transducers
If there is a marked narrowing of the artery at some point, the speed of the blood will …. at that point according to …. Equation.
increase ; doppler
Lower frequency ultrasound in the range from …. to … Hz is used in ultrasonic cleaning devices.
20K ; 50K
A property of waves, called …. occurs when they bend around
obstacles and move through narrow spaces.
refraction
The source transducer in ultrasound techniques converts ….
energy into ultrasound and the receiving transducer converts
ultrasound back into an …. , which can be processed for
display.
electrical ; electric signal