A boy timed 30 oscillations of a certain pendulum thrice and obtained 1min. 10s, 1min. 12s and 1min. 7s respectively.The mean period of oscillation of the pendulum is

tizkid

10 years ago

total time is 209 not 219 n whereas n=30 not 90.

Ans is D

khalilibrahimyz

6 years ago

The answer must be D since n =30, ≠90

Hayormidae

11 years ago

The ans is not there:

Total time:(3x60)+10+12+7=219

period= t/n=219/90

=2.43sec