A Piece of string 5.3-m long has a mass of 15.o g what must the tension in the string be to make the wavelength of a 125- Hz wave 120.0 cm

1 answer

L =5.3 m, m = 0.015 kg, λ = 0.2 m,
f = 125 Hz, T = ?
Velocity in the stretched string is
v = sqrt(T/mₒ),
T =mₒ•v²,
mₒ = m/L,
λ = v/f, v = λ•f,
T =mₒ•v² = m • (λ•f)² /L =0.015•(1.2•125)²/5.3 = 63.7 N.