Answer:
The fundamental frequency is 10 Hz
Step-by-step explanation:
The frequency of the fundamental mode of the string is given by;

where;
L is length of the string = 2.5 m
T is tension of the string, = 10 N
μ is mass per unit length = m / L = 0.01 / 2.5 = 0.004 kg/m
Substitute the given values and solve for the frequency;

Therefore, the fundamental frequency is 10 Hz