Answer: Tension = 47.8N, Δx = 11.5×
m.
Tension = 95.6N, Δx = 15.4×
m
Explanation: The speed of a wave on a string under tension can be determined using the following:

denotes tension (N)
μ refers to linear density (kg/m)
Calculating the velocity:


0.0935 m/s
Distance a pulse traveled in 1.23ms:


Δx = 11.5×
With a tension of 47.8N, the distance a pulse will cover is Δx = 11.5×
m.
When tension is doubled:



|v| = 0.1252 m/s
Distance in the same time:


15.4×
With the increased tension, it moves
15.4×
m