Answer:
5 m/s
Step-by-step explanation:
The speed of a wave in a string is related to the tension in the string by the equation
![v=\sqrt{(T)/(\mu)}](https://img.qammunity.org/2021/formulas/physics/college/1hlhmeuv3pox4tzc9kk8h08b2cx7bd2yzp.png)
where
v is the speed of the wave
T is the tension in the string
is the linear density of the string
We can rewrite the equation as
![(√(T))/(v)=√(\mu)](https://img.qammunity.org/2021/formulas/physics/middle-school/bm1lcs3o8af0btg2edmyiqezo0b2lo20vw.png)
In this problem, the tension in the string is changed; however, its linear mass density remains constant. So we can write:
![(√(T_1))/(v_1)=(√(T_2))/(v_2)](https://img.qammunity.org/2021/formulas/physics/middle-school/k8u6e9s4wrcida5xql5zc1cps6fvh9s2my.png)
where:
T1 = 40 N is the initial tension in the string
v1 = 10 m/s is the initial speed of the wave
T2 = 10 N is the final tension in the string
Solving for v2, we find the final speed of the wave:
![v_2=v_1 \sqrt{(T_2)/(T_1)}=(10)\sqrt{(10)/(40)}=5 m/s](https://img.qammunity.org/2021/formulas/physics/middle-school/z5fprb27i7lxnixuv68i57l2wbichxxqrz.png)