The tension in a string with a linear density of 0.0010 kg/m is 0.40 N. A 100 Hz sinusoidal wave on this string has a wavelength of:
A) 0.05 cm
B) 2.0 cm
C) 5.0 cm
D) 20 cm
E) 100 cm

Question

Quizplus · Accepted Answer

The speed of a wave on a string is given by v = sqrt(T/u), where T is the tension and u is the linear density. 
v = sqrt(0.40 N / 0.0010 kg/m) = 20 m/s

The wavelength is given by lambda = v/f, where f is the frequency.
lambda = 20 m/s / 100 Hz = 0.20 m = 20 cm.

Therefore, the wavelength of the wave on this string is 20 cm, which corresponds to choice D.

The Tension in a String with a Linear Density of 0.0010