A boy timed 30 oscillations of a certain pendulum thrice ...
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
0.14s
0.43s
2.32s
6.97s
Correct answer is C
Total time = (3 x 60) + 29
= 209sec
period \(\frac{t}{n}\) = \(\frac{209}{90}\)
= 2.32sec