A pendulum swings through an angle of 30° and describes an arc 8.8 cm in length. Find the length of the pendulum.

Given:

Angle made by the pendulum = 30°

Length of the arc made by the pendulum = 8.8 cm

Then the length of the pendulum is equal to the radius of the sector made by the pendulum.

Let the length of the pendulum be ‘r’.

∵ Length of arc = × 2πr

∴ We have,

× 2πr = 8.8

× 2 × 3.14 × r = 8.8

r = 8.8 ×

r = 16.8 cm

__Hence, the length of the pendulum is 16.8 cm.__

19