Trigonometry Math 240

Question

The minute hand of a clock is 3 cm long. How far does the tip of the minute hand move in 1 hour and 10 minutes? Give to decimal places.

Answer 1

In 1 hour the minute hand makes a complete traversal of the circle, radius 3 cm.

The circumference of the circle is 2(π)r = 2(π)(3) = 6(π).

In 10 minutes, the minute hand will move 10/60 = 1/6th the length of the circumference, or (1/6)6(π) = π

So in 1 hr and 10 minutes, the minute hand moves 6π + π = 7π cm.

In to? (two)? decimal places, 7(3.1415926) = 21.99 cm