Question

practice: running track measures

1. the formula to find the circumference (c), the distance around a circle, is ( 2 pi r ). find the distance once around the running track when ( r = \frac{1}{10} ) of a mile. use ( pi = 3.14 ).

Explanation:

Step1: Identify the formula and values

The formula for the circumference of a circle is \( C = 2\pi r \). We know that \( r=\frac{1}{10} \) mile and \( \pi = 3.14 \).

Step2: Substitute the values into the formula

Substitute \( r=\frac{1}{10} \) and \( \pi = 3.14 \) into the formula \( C = 2\pi r \). So we have \( C=2\times3.14\times\frac{1}{10} \).

Step3: Perform the multiplication

First, calculate \( 2\times3.14 = 6.28 \). Then, multiply \( 6.28\times\frac{1}{10} \). Since multiplying by \( \frac{1}{10} \) is the same as dividing by 10, we get \( 6.28\div10 = 0.628 \).

Answer:

The distance once around the running track is \( 0.628 \) miles.