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
-
A.
0.14s -
B.
0.43s -
C.
2.32s -
D.
6.97s
Correct Answer: Option C
Explanation
Total time = (3 x 60) + 29
= 209sec
period (frac{t}{n}) = (frac{209}{90})
= 2.32sec