ANSWER
[tex]2.0m[/tex]EXPLANATION
First, we have to find the initial length of the pendulum by applying the formula for the period:
[tex]T=2\pi\sqrt[]{\frac{L}{g}}[/tex]where L = length of the pendulum
g = acceleration due to gravity
Hence, we have that the initial length of the pendulum is:
[tex]\begin{gathered} 2=2\pi\cdot\sqrt[]{\frac{L}{10}} \\ \frac{2}{2\pi}=\sqrt[]{\frac{L}{10}} \\ (\frac{2}{2\pi})^2=\frac{L}{10} \\ \Rightarrow L=10\cdot(\frac{2}{2\pi})^2 \\ L=1.0m \end{gathered}[/tex]Hence, the new length of the pendulum after it is doubled is:
[tex]\begin{gathered} L=2\cdot1.0 \\ L=2.0m \end{gathered}[/tex]That is the answer.
