Answer:
n = 10 beats
Explanation:
Given:
- Frequency of note f1 = 151 Hz
- Frequency of note f2 = 155 Hz
- The total time they ring t = 2.5 s
Find:
How many beats are heard
Solution:
- The frequency of beat (fb) is the difference between the two frequencies of notes as follows:
fb = f2 - f1
fb = 155 - 151
fb = 4 Hz
- The number of beats per second is also called beat frequency:
n = fb*t
n = 4*2.5
n = 10 beats
Answer:
Explanation:
To find the amplitude of the sound, we must first determine the wavelength and the phase difference between the two speakers.
For the wavelength;
Recall that, the separation between two successive max. and min. intensity points are 
Thus; for both speakers; the wavelength of the sound is:


λ = 80 cm
The relation between the path difference(Δx) and the phase difference(Δ∅) is:

where;
Δx = 10 cm
λ = 80 cm
Δ∅ = π rad
∴







Suppose both speakers are placed side-by-side, then the path difference between the two speakers is: Δx = 0 cm
Thus, we have:



∴
The amplitude of the sound wave if the two speakers are placed side-by-side is:



A = 0.765a