## Sunday, November 20, 2011

### Glenesse's Math Question

My question is # 28 in chapter 2.4.

Question:

The period, t, in seconds, of a pendulum is the time for a complete swing back and forth. The period can be calculated from the length, l, in metres, of the pendulum using the formula t = √4l. Determine the period of a pendulum with each of the following lengths. Express each answer to the nearest hundredth of a second.

a) 1.6 m
b) 2.5 m
c) 50 cm

a) The period of a pendulum with the length of 1.6 m is 2.53 (s) seconds.

I first multiplied the length, which was 1.6, by 4 and got 6.4. I then square rooted that and got 2.53 s.

b) The period of a pendulum with the length of 2.5 m is 3.16 (s) seconds.

I first multiplied the length, which is 2.5, by 4 and got 10. I then square rooted that and got 3.16 s.

c) The period of a pendulum with the length of 50 cm is 1.41 (s) seconds.

I first multiplied the length, which is 50, by 4 and got 200. I then square rooted that and got 14.14, but I had to divide that by ten because we need to get from cm to m. I then got 1.41 s.