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.