A long string is constructed by the joining of ends of two shorter strings. The
ID: 1483029 • Letter: A
Question
A long string is constructed by the joining of ends of two shorter strings. The tension in the strings is the same but STRING 2 has 4 times the linear mass density than STRING 1. When a sinusoidal wave passes from STRING 1 to STRING 2:
A. FREQUENCY DECREASES BY A FACTOR OF 2
B. WAVELENGTH INCREASES BY A FACTOR OF 2
C. FREQUENCY DECREASES BY A FACTOR OF 4
D. WAVELENGTH DECREASES BY A FACTOR OF 2
E. WAVELENGTH DECREASES BY A FACTOR OF 4.
I thought answer B but I only get one chance and want to be sure.
Explanation / Answer
speed v1 = sqrt(T/u1)
V2 = sqrt(T/u2)
u2 = 4u1
V2 = sqrt(T/4u1) = v1/2
v2 = v1/2
v1 = lambda1*f
v2 = lambda2*f
v2/v1 = lambda2/lambda1
lambda2 = lambda1/2
wavelength2 = wavelength1 /2
D. WAVELENGTH DECREASES BY A FACTOR OF 2