Answer:
(a). The lowest frequency is 64.7 Hz.
(b). The next two resonant frequencies for the bugle are 129.4 Hz and 194.2 hz.
Explanation:
Given that,
Length = 2.65 m
Speed of sound = 343 m
We need to calculate the wavelength
Using formula of wavelength

Put the value into the formula


(a). We need to calculate the lowest frequency
Using formula of frequency

Put the value into the formula


(b). We need to calculate the next two resonant frequencies for the bugle
Using formula of resonant frequency


Put the value into the formula


For third frequency,


Put the value into the formula


Hence, (a). The lowest frequency is 64.7 Hz.
(b). The next two resonant frequencies for the bugle are 129.4 Hz and 194.2 hz.