Acoustics Answers

The velocity of a particle moving in the xy plane is given by , with in meters per second and t (> 0) in seconds. At t = 4.8 s and in unit-vector notation, what are (a) the x component and (b) the y component of the acceleration? (c) When (if ever) is the acceleration zero? (d) At what positive time does the speed equal 10 m/s?

A whistle is rotated along a circular path of radius 1 m, The whistle completes two rotations per second along the circular path. An observer stays outside the circular path but in the same plane with the circular path. Calculate the musical interval as heard by die observer between maxm. and minm. frequencies. Given velocity of sound 330 m/s.

4. A whistle is rotated along a circular path of radius 1 m, The whistle completes two rotations per second along the circular path. An observer stays outside the circular path but in the same plane with the circular path. Calculate the musical interval as heard by die observer between maxm. and minm. frequencies. Given velocity of sound 330 m/s.

a stretched rope having linear mass density 5 kg per meter is under a tension of 80 N.The power that has to be supplied to the rope to generate harmonic waves at a frequency of 60 Hz and an amplitude of 6 cm is ?

A sound wave travelling in glycerine, with a density 1260kg/m^3 is represented by the following plane wave equation:

S(x,t) = (0.5mm)sin[(1.1rad/m)x-(2200rad/sec)t]

(a)Is the sound wave moving left or right with respect to the horizontal?
(b)What is the displacement amplitude?
(c)What is the frequency?
(d)What is the period?
(e)What is the wavelength?
(f)What is the phase speed of the sound wave?
(g)What is the maximum medium particle velocity?
(h)What is the maximum acoustic pressure?
(i)What is the specific acoustic impedance for the plane wave in the glycerine?
(j)What is the average intensity?

Please help. I think I'm able to solve some of these questions but I need help please

Sound waves get reflected so that they superimpose each and resonance occur. Also sound waves are absorbed so that echo is not heard in crowded hall (although it is heard if hall is empty). And in open organ pipe resonance occur because it encounter with free air outside the tube and reflects back. My question is, if air can reflect the sound wave, how can we hear sound? And what are the conditions when sound waves get reflected or absorbed?