Answer:
The wave speed would be increased by
![√(2)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/zk4ls2i7rszmygzgqi2kkfexuqtms266jg.png)
Step-by-step explanation:
As the formula for the wave speed of string v when subjected to tension T is:
![v = \sqrt{(T)/(\mu)}](https://img.qammunity.org/2021/formulas/physics/college/imasljketj3s3czubxazr3tnxcca4cliz2.png)
where μ is the string density (mass per length), which is constant for this case.
So when a string is subjected to tension 2T then
![(v_2)/(v) = (√(2T/\mu))/(√(T/\mu))](https://img.qammunity.org/2021/formulas/physics/college/ewammh3rh3s96t3y0riy6zb7c60yl4ow5x.png)
![(v_2)/(v) = \sqrt{(2T)/(T)(\mu)/(\mu)} = √(2)](https://img.qammunity.org/2021/formulas/physics/college/3weluh8dvhw0isc0t7qfup4m5glus7s9l5.png)
![v_2 = √(2)v](https://img.qammunity.org/2021/formulas/physics/college/8cjpc1j19c5qb6e898yvw4q0raj15a6wm2.png)
So the wave speed would be increased by
![√(2)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/zk4ls2i7rszmygzgqi2kkfexuqtms266jg.png)