Final answer:
The pulse sent down strings of different linear mass densities will travel faster in the lower density string due to the relationship between tension and mass density impacting wave speed, resulting in different velocities and amplitudes at the interface.
Step-by-step explanation:
When a high-linear mass density string is attached to a string with a lower linear mass density and a pulse is sent down the strings, the wave speed is not the same in both strings due to their differing mass densities.
Assuming that the tension is the same across both strings, the pulse will travel faster in the low density string because wave speed in a string is determined by the tension and the linear mass density, expressed by the formula v = √(T/μ), where v is the wave speed, T is the tension, and μ is the linear mass density.
At the interface where the two strings with different mass densities are spliced, the incident pulse will partly reflect and partly transmit into the second string. Since the wave speed is higher in the string with the lower linear mass density, the pulse will speed up as it enters this string.
However, due to the conservation of energy and the continuous tension, the amplitude of both the transmitted and the reflected waves will be less than the amplitude of the incident wave.
The density and linear density are key to understanding the behavior at the boundary; when the string leads to an experimental density that is too high or too low, it can affect the amplitude and phase of the waves involved, which could result in inaccurate measurements in an experimental setup.