Question

Find the length of a simple pendulum whose time period of oscillation is 1.8s at a place where g = 9.8 m/s2.

Answer 1

Answer:

As we know the T=2π√L/g So 1.8=2π√L/9.8 1.8/2*3.14=√L. /9.8 (0.286)^2=L/9.8 0.081*9.8=L L=0.801

Answer 2

Answer:

The length of the pendulum is 80 cm.

Explanation:

• Time period: Time period of a pendulum is the time taken to complete one oscillation.
• Time period is indicated by 'T' and its unit is second.
• Length of a pendulum: The distance from point of suspension to the centre of bob of a pendulum is called length of the pendulum,
• Length of a pendulum is expressed by 'L' and its unit is metre.
• Formula for time period: T = 2π√(L/g)
• Calculation: Here T = 1.8 s, g = 9.8 m/s²

        From the above equation, 1.8 = 2π × √(L/9.8)

       By taking square on both sides, 1.8² = 4π² × L/9.8

                                                          ⇒ L = 1.8² × 9.8/4π²

                                                          ⇒ L = 1.8² × 9.8/4π² = 0.804 m

                                                                                            = 80 cm

    ∴The length of the pendulum is 80 cm.