The time period of a 1 m long pendulum approximates to 2 s. The time period ($T$) of a simple pendulum for small oscillations is given by the formula $T = 2\pi \sqrt{\frac{L}{g}}$, where $L$ is the length of the pendulum and $g$ is the acceleration due to gravity. Given length $L = 1$ m. Taking the standard value of $g \approx 9.8$ m/sĀ² and $\pi \approx 3.14$: $T = 2 \times 3.14 \times \sqrt{\frac{1}{9.8}} \approx 6.28 \times \sqrt{0.102} \approx 6.28 \times 0.319 \approx 2.005$ s. A common approximation for calculation purposes is sometimes $\pi^2 \approx g$, which gives $T = 2\pi \sqrt{\frac{1}{\pi^2}} = 2\pi \times \frac{1}{\pi} = 2$ s. Both calculations yield a value very close to 2 seconds.