A sinusoidal wave of frequency 250Hz travels along a stretched string with speed 200ms−1. The wave then enters a second string in which the tension is doubled while the linear mass density remains the same. Taking the speed in a string to vary as the square root of tension, by what approximate percentage does the wavelength change as the wave enters the second string?
a) 100% increase
b) 41% increase
c) 29% increase
d) 58% increase