The function L = 0.8T2 models the relationship between L, the length in feet of a pendulum, and T, the period in seconds of the pendulum. Which value is closest to the period in seconds for a pendulum that is 30 feet long?

answer choices
5.4 seconds
4.9 seconds
6.8 seconds
6.1 seconds

5.4 seconds

Why is the answer 6.1

To find the period for a pendulum that is 30 feet long, you need to substitute L = 30 into the equation L = 0.8T^2 and solve for T.

30 = 0.8T^2
30 / 0.8 = T^2
37.5 = T^2
T = sqrt(37.5)
T ≈ 6.1237 seconds

So the closest value to the period in seconds for a pendulum that is 30 feet long is 6.1 seconds, rounded to the nearest tenth.