Question

Find the angle in radian through which a pendulum swings if its length is 75 and the tip describes an arc of length 21 cm .

Answer 1

We know that $l=r\theta$

Here,$l=$ length of arc$=21$cm

$r=$radius$=$length of pendulum$=75$cm

We have $l=r\theta$

$\Rightarrow 21=75\times \theta$

$\Rightarrow \theta =\frac{21}{75}=\frac{7}{25}$radian