Answer:
12.35022 m/s
Explanation:
f = Frequency = 3.9 rev/s
r = Length of string = 0.504 m
Time period is given by
[tex]T=\dfrac{1}{f}\\\Rightarrow T=\dfrac{1}{3.9}\\\Rightarrow T=0.25641\ s[/tex]
The time period is 0.25641 s
The speed is given by
[tex]Speed=\dfrac{Distance}{Time}[/tex]
[tex]v=\dfrac{2\pi r}{T}\\\Rightarrow v=f(2\pi r) \\\Rightarrow v=3.9\times 2\pi\times 0.504\\\Rightarrow v=12.35022\ m/s[/tex]
The speed of the ball is 12.35022 m/s