Question

Please explain I don’t understand it !

Answer 1

Answer: L = 3.6 ft

Explanation:

`T=2\pi \bigg\sqrt{(L)/(32)}\\\\\\\\2.1=2\pi\bigg\sqrt{(L)/(32)}\\\\\\(2.1)/(2\pi)=\bigg\sqrt{(L)/(32)}\\\\\\\\\bigg((2.1)/(2\pi)\bigg)^2=(L)/(32)\\\\\\32\bigg((2.1)/(2\pi)\bigg)^2=L\\\\\\\large\boxed{3.5746=L}`