Answer:
2820 N
Explanation:
Let assume that
Ft = µ(2fL)^2
tension = µ(2*frequency*length)²
wavelength = 2*length
In general, for a wire fixed at both ends,
λ_n = 2L/n
n is the harmonic number
v = f_n * λ_n = f_n * 2*L/n
= √(T/µ)
= √(T/(ρA))
so
T = (f_n * 2 * L / n)² * ρA
Given that,
f_3 = 512 Hz,
L = 1.2 m,
n = 3,
ρ = 21.4 × 10⁻³ kg/m³,
and with the radius can easily find the area A
A = πr²
= π(0.005)²
= 7.85 ×10⁻⁵
When I plug these values in, I get tension T = 2820 N.
