The period of a pendulum is given by:
[tex]T=2\pi\sqrt{\frac{L}{g}}[/tex]where L is the length of the sting and g is the acceleration of gravity. In this case the length of the string is 0.250 m, plugging the values we have:
[tex]\begin{gathered} T=2\pi\sqrt{\frac{0.250}{9.8}} \\ T=1.00 \end{gathered}[/tex]Therefore, the period is 1.00 s
