A long string is constructed by joining the ends of two shorter strings.The tension in the strings is the same but string I has 4 times the linear mass density of string II.When a sinusoidal wave passes from string I to string II:
A)the frequency decreases by a factor of 4
B)the frequency decreases by a factor of 2
C)the wave speed decreases by a factor of 4
D)the wave speed decreases by a factor of 2
E)the wave speed increases by a factor of 2

Question

Quizplus · Accepted Answer

The wave speed on a string is given by $ v = \sqrt{\frac{T}{\mu}} $, where $ T $ is the tension and $ \mu $ is the linear mass density. Since string I has 4 times the linear mass density of string II, the wave speed in string II will be $ \sqrt{4} = 2 $ times greater than in string I.

A Long String Is Constructed by Joining the Ends of Two