Solve the problem.
-A pendulum swings through an arc 80 inches long on its first swing. Each swing thereafter, it swings only 70% as far as on the previous swing. How far will it swing altogether before coming to a complete stop? If necessary,
Round to the nearest inch.
A) 267 in.
B) 114 in.
C) 229 in.
D) 133 in.

Question

Quizplus · Accepted Answer

The total distance the pendulum swings can be found using the formula for the sum of an infinite geometric series, $S = \frac{a}{1 - r}$, where $a$ is the first term and $r$ is the common ratio. Here, $a = 80$ inches and $r = 0.70$. Thus, $S = \frac{80}{1 - 0.70} = \frac{80}{0.30} = 266.67$ inches, which rounds to 267 inches.

Solve the Problem. -A Pendulum Swings Through an Arc 80 Inches Long on Inches