Question

What is the length of a pendulum that has a period of 3.89 seconds ?

A. 365.9 m
B. 3.96m
C. 0.966m
D. 3.76m

Answer 1

The formula to solve the length of a pendulum is:


`L=( (T)/(2 \pi ) ) ^(2) g`

Where:
L=length
T=period
g=9.8m/s^2 (This is constant)

Now just fill in what you know and solve for what you don't know. Based on the question, you know that the period is 3.89s.


`L=( (T)/(2 \pi ) ) ^(2) g`

`L=( (3.89s)/(2 \pi ) ) ^(2) 9.8m/s^(2)`

`L=( 0.62s) ^(2)9.8m/s^(2)`

`L=(0.3844s^(2))(9.8m/s^(2))`

`L=3.76m`

The answer is then D.