Question -
Answer -
(a) Yes; Speed = 20 m/s, Direction = Right to left
(b) 3 cm; 5.73 Hz
(c) 
(d) 3.49 m
Explanation:
(a) The equation of a progressive wave travelling from rightto left is given by the displacement function:
y (x, t)= a sin (ωt + kx + Φ) … (i)
The given equation is:
On comparing both the equations, we findthat equation (ii) represents a travelling wave, propagating from rightto left.
Now, using equations (i) and (ii),we can write:
ω = 36 rad/s and k = 0.018m–1
We know that:
and 
Also,
v = νλ
Hence, the speed of the given travelling wave is 20 m/s.
(b) Amplitude of the given wave, a = 3 cm
Frequency of the given wave:
(c) On comparing equations (i) and (ii), we findthat the initial phase angle,
(d) The distance between two successive crests or troughs isequal to the wavelength of the wave.
Wavelength is given by the relation:
