Question

The period of a pendulum is the time the pendulum takes to swing back and forth. The function L=0.81t^2 relates the length L in feet of a pendulum to the time t in seconds that it takes to swing back and forth. A convention center has a pendulum that is 140 feet long. Find the period

Answer 1

Answer: Period = 13.15 s

Solution:  

The period of a pendulum is the time of pendulum takes to swing back and forth.  

Function $L=0.81t^2$

Where,  

L is length of pendulum in feet  

T is time of pendulum in seconds  

We have to calculate the time of pendulum whose length is 140 feet.  

So, we substitute L=140 into formula $L=0.81t^2$ and to solve for t  

We get t,  

$140=0.81t^2$

$t^2=\frac{140}{0.81}$

$t=\sqrt{172.84}$

$t=13.15$s

Period = 13.15 s

Answer 2

Answer: Period = 13.15 s