I'm stuck?

Question

A simple 2.00m-long pendulum oscillates in a location where g =9.8. How many complete oscillations does it make in 5. minutes?
I use the formula and find T, then I divide it by whatever I got. but I don't get the answer. The answer is 105 oscillations. What am I doing wrong?

Answer 1

Quite easy-:

Time Period = 2 pi x sqrt (pendulum length / gravity)

Therefore-:
2 x pi x sqrt (2/9.8) = 2.83845379 seconds per oscillation

Now Pendulum swings for 5 minutes = 300 seconds

300 / 2.83845379 = 105.69 oscillations in 5 minutes !! Easy....next :o)

Answer 2

5min =5*60sec=300sec

f=1/T
no of oscilations=300/T