Question

A bicycle wheel with a radius of 14 inches travels one mile (5,280 feet). Approximately how many revolutions does the wheel make?

Answer 1

ANSWER

720 revolutions.

EXPLANATION

The radius of the bicycle wheel is 14 inches.

1foot =12 inches.

This implies that

$r = \frac{14}{12} = \frac{7}{6} ft$

In one revolution, the bicycle covers

$2\pi \: r \: ft$

The number of revolution in 5,280 feet is

$\frac{5280}{2\pi \: r} = \frac{5280}{2 \times \pi \times \frac{6}{7} } = 720.2897996$

This is approximately 720 revolutions.