Question

The hour hand of a clock is 4.5 cm long. What distance does its tip cover in 12 hours?

• A. 38 cm
• B. 336 cm
• C. 28.28 cm
• D. 12 cm

Answer 1

The correct option is C

28.28 cm

A clock can be considered as a circle then hour hand is equal to the radius of the circle.
Given, length of the hour hand, r = 4.5 cm
Here, the distance covered by the hour hand is the circumference of the circle.
$\Rightarrow$ Distance covered in 12 hours (one complete rotation) = $2\times \pi r$
$=2\times \frac{22}{7}\times 4.5cm=28.28cm$
Therefore, the distance covered will be 28.28 cm.