The period of a pendulum is the time the pendulum takes to swing back and forth. the function upper l equals 0.81 t squared 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 50 feet long. find the period.

It is given that the time period of a pendulum(T) is the time(t) the pendulum take to swing back and forth.

Given the function:         ......[1]

where L is the length in feet of a pendulum and t is the time in second.

It is given also, a convention center has a pendulum (L) = 50 ft long.

Substitute the value of L in [1] to solve for t;

Divide both sides by 0.81 we get;

Simplify:

or

sec

therefore, period of pendulum (T), is 7.86 sec (nearest to hundredths)