Question

If I drive 8.5 laps around a circular race track and during that drive I go 32 mi, what is the radius of the track? Round to two decimal places.

Answer 1

Answer: The radius of the track = 0.64 mi

Step-by-step explanation:

Fr circular track , Total distance covered around it = (Number of laps) x (Circumference)  

As per given,

32 mi = 8 x (Circumference)

Circumference = $\dfrac{32\ mi}{8}=4\ mi$

Also, Circumference = $2\pi r$ , where r= radius so,

$2\pi r=4\ mi\\\\\Rightarrow\ r=\dfrac{4}{2\pi}\\\\\Rightarrow\ r=\dfrac{2}{\pi}$

Put $\pi= 3.14$

$r=\dfrac{2}{3.14}\approx0.64\ mi$

Hence, the radius of the track = 0.64 mi