What must be the tension of a string 202 cm long and 3 x 10-2 Kg / m per unit length (µ) for it to emit a sound of 78 Hz?

2980 N

Explanation:

The fundamental frequency of a string is:

f₁ = √(T/µ) / (2L)

78 Hz = √(T / (0.03 kg/m)) / (2 (2.02 m))

315.12 m/s = √(T / (0.03 kg/m))

99,300 m²/s² = T / (0.03 kg/m)

T = 2980 N

you would expect a sound wave to speed up. - b)

2b2t

explanation:

2b2t