Question

 If two waves both have frequencies of 800 Hz, can they produce beats? If you answer ‘yes", determine their beat frequency. If you answer ‘no', explain why they cannot produce beats. (b) If waves of frequencies 900 Hz and 902 Hz interfere, determine the beat period of the wave that they produce.

Answer 1

Answer:

(a)  No , we will not hear any beat frequency

(b) The beat period of the wave that they produce is 2.0 Hz

Explanation:

(a) No , we will not hear any beat frequency

Explanation

Beats occur when two waves of nearby frequencies overlap and create a new resultant wave for which maxima and minima amplitude of resultant wave  varies at a particular position is space with time . The number of beats per second equals the difference in frequency between the two interfering waves .

                 If the beats occur more often than roughly 20 or 30 times per second, we no longer hear them as beats. Our ears are not fast enough to respond to events happening quickly. So for beats to occur there must be some difference between the interfering frequencies .

(b) Since the number of beats per second equals the difference in frequency between the two interfering waves.

$f_{beat}=\left | f_1-f_2 \right |$

=>$f_{beat}=\left | 902-900 \right |\, Hz=2.0\, Hz$

Thus the beat period of the wave that they produce is 2.0 Hz