Question

A pendulum of length 10 cm is hanged by wall making an angle 3° with vertical. It is swinged to position B. Time period of pendulum will be

• A. p/5 sec
• B. $\frac { 2 \pi } { 15 }$ sec
• C. p/6 sec
• D. Subsequent motion will not be periodic

Answer 1

Answer: (B)

$\frac { 2 \pi } { 15 }$ sec

Answer 2

Time taken by pendulum in going from A to B

= where T = 2p

Time taken by pendulum in going from B to C

= $\frac { \mathrm { T } } { 12 }$

\ Time period of pendulum

=

= $\frac { 2 } { 3 }$.$\frac { 2 \pi } { 15 }$sec

Altier :

T¢ = $\frac { 240 } { 360 }$ . T

=