Question

14) A wave of wavelength 30cm is travelling through a 300m long wire whose mass is 15kg.
If the wire is under tension of IkN,
compute the speed and frequency of the wave.
(December 2019)
​

Answer 1

Explanation:

Hope it's helpful to you

Answer 2

Given info : A wave of wavelength 30cm is travelling through a 300m long wire whose mass is 15kg.

To find : If the wire is under tension of 1 kN, compute the speed and frequency of the wave.

solution : using formula, v = √{T/μ}

where, T = tension and μ = mass per unit length of wire.

here T = 1kN = 1000 N , μ = 15kg/300 m = 1/20 kg/m

now v = √{1000/(1/20)} = √(20000) = 100√2 m/s

now using formula, v = λf

wavelength, λ = 30 cm = 0.3 m

speed, v = 100√2 m/s

so, f = v/λ = 100√2/0.3 = 1000√2/3 = 471.4 Hz

Therefore speed and frequency of the wave are 100√2 m/s and 471.4 Hz respectively.