Find the angle in radian through which a pendulum swings if its length is 75 cm and the tip discribes an arc of length:
i) 10 cm ii) 15 cm iii) 21 cm

Explanation

i) Length of swing be `theta`.
then `theta=l/r rArr theta=10/75` radian =`2/15` radian Ans.
ii) Length of pendulum( r)=75 cm
Length of arc formed by the tip of pendulum
(l)=15 cm
Length angle of swing be `theta`.
then `theta=l/r rArr theta=15/75 = 1/5` radian
Therefore, angle formed by pendulum `=1/5` radian. Ans
iii) Length of pendulum (r) = 75 cm,
Length of arc formed by the tip of pendulum (l) =21 cm
Let angle swing be `theta`.
then `theta=l/r rArr theta=21/75 = 7/25` radian
Therefore, angle formed by pendulum `=7/25` radian. Ans.