Two plane harmonic sound waves are expressed by the equations.
y 1 (x, t) = A cos (0.5 πx – 100 πt)
y 2 (x, t) = A cos (0.46 πx – 92 πt)
(All parameters are in MKS):
(i) How many times does an observer hear maximum intensity in one second?
Text Solution
Verified by ExpertsCHECK THE SOLUTION
(i)
Sol. 
, f 1 = 50
2πf 2 = 92π, f 2 = 46
beat frq = 50 – 46 = 4
(ii)
Sol. v = 
= 
Speed v = 200
(iii)
Sol. At x = 0,
y = y 1 + y 2 = 2A cos 96 πt cos 4 πt
For y = 0 cos 96πt = 0
or cos 4πt = 0
for 0 < t < 1 cos 4πt become 0 at t = 
, 
, 
, 
sec
but cos 96πt is not 0 at these values but cos 96πt become 0, 96 times in 1 sec.
Therefore net amplitude become zero 100 times.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems