When a car approaches you, the sound waves that reach you have a shorter wavelength and a higher frequency. You hear a sound with a higher pitch. When the car moves away from you, the sound waves that reach you have a longer wavelength and lower frequency.
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An approaching source moves closer during period of the sound wave so the effective wavelength is shortened, giving a higher pitch since the velocity of the wave is unchanged. Similarly the pitch of a receding sound source will be lowered.
The Doppler effect is an effect observed in light and sound waves as they move toward or away from an observer. One simple example of the Doppler effect is the sound of an automobile horn. Picture a person standing on a street corner. A car approaches, blowing its horn.
Comparing two waves of the same wavelength, a higher frequency is associated with faster movement. Comparing two waves of different wavelengths, a higher frequency doesn't always indicate faster movement, although it can. Waves of different wavelengths can have the same frequency.
The pitch of a sound is our ear's response to the frequency of sound. Whereas loudness depends on the energy of the wave. ... The pitch of a sound depends on the frequency while loudness of a sound depends on the amplitude of sound waves.
Explanation:
Given that,
Voltage of household line, V = 110 V
Power of the hairdryer, P = 1650 W
During use, the current is about 1.95 cm from the user's hand.
(a) Power is given by :
(b) Again the power is given by :
R is resistance of the dryer
(c) The magnetic field produced by the dryer at the user's hand is given by :
Hence, this is the required solution.
The main difference between the model of the atom proposed by Greek philosophers and the model proposed centuries later by Dalton is that the Greek one was mainly speculative and philosophical - it wasn't based on real evidence, but on their suggestions and thoughts about the matter. On the other hand, Dalton had the means to prove his theory using viable evidence, not just speculations.
<span>If the Earth rotated more slowly about its axis, your apparent weight would
A) increase.
B) decrease.
C) stay the same.
D) be zero.
</span>A) increase.
Answer:
Explanation:
Given
1 mole of perfect, monoatomic gas
initial Temperature
Work done in iso-thermal process
=initial pressure
=Final Pressure
Since it is a iso-thermal process therefore q=w
Therefore q=39.64 J
(b)if the gas expands by the same amount again isotherm-ally and irreversibly
work done is
