In order to solve this, we just need to solve for L, because we are told what T is (3.2).
Here is how we set up the equation:
[tex]3.2=2 \pi \sqrt{L/980} [/tex]
We can now solve for L. First, let's divide both sides by 2 pi. Now, our equation is:
[tex] \frac{3.2}{2 \pi } = \sqrt{L/980} [/tex]
Now, we square both sides to get rid of the square root. This is equal to:
[tex] \frac{ 3.2^{2} }{ (2 \pi )^{2} } =L/980=0.2594[/tex]
Now, we have 0.2594 = L/980. We finish the problem by multiplying both sides by 980. This becomes
254 = L.
So, the answer is C, 254 centimeters.
