Answer:
(a) and (c) Third harmonic frequency will be 7.75 Hz
(b) Fundamental frequency will be 2.5833 Hz
Explanation :
Mass of the rope m = 5 kg
(b) We have given length of the rope l = 15 m
Wave speed v = 77.5 m /sec
We know that frequency is given by [tex]f=\frac{v}{\lambda }[/tex]
Here [tex]\lambda =2l[/tex]
So [tex]f=\frac{v}{2l}=\frac{77.5}{2\times 15}=2.5833Hz[/tex]
(a) and (c) Frequency of the third harmonic of the rope will be = 3× fundamental frequency = 3×2.5833 = 7.75 Hz