A horizontal string of linear density 0.01 kg/m is stretched by a hanging mass of 10 kg over a smooth pulley. A vibrator of frequency 50 Hz produces transverse waves on the horizontal part of the string. Take g = 10 m/s². If the wavelength is N/5 metres, find N.
Physics · Wave Motion · question based on string wave
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Question

A horizontal string of linear density 0.01 kg/m is stretched by a hanging mass of 10 kg over a smooth pulley. A vibrator of frequency 50 Hz produces transverse waves on the horizontal part of the string. Take g = 10 m/s². If the wavelength is N/5 metres, find N.

Physics · Wave Motion · question based on string wave

G1 Physics · Accepted Answer

The tension in the string is T = Mg = 10×10 = 100 N. Wave speed is v = √(T/μ) = √(100/0.01) = √10000 = 100 m/s. Using v = fλ, λ = v/f = 100/50 = 2 m. Given λ = N/5 m, N/5 = 2. Therefore, N = 10.