Class 11 NEET Physics Oscillations Questions

Frequency of the pendulum
vl=5=

1

2π

√

g

5

;vl=20=

1

2π

√

g

20

∴

vl=5

vl=20

=√

20

5

=2 ⇒vl=5=2vl=20
As shorter length pendulum has frequency double the larger length pendulum. Therefore shorter pendulum should complete 2 oscillations before they will be again in phase.