Question 58

The minute hand of a watch is 1.5 cm long. How far does its tip move in 40 minutes?

Solution

In this case, the radius of the circle traced by the minute hand is 1.5 cm.

Circumference = 2πr = 2π(1.5) = 3π cm

The minute hand covers this distance in 60 minutes.

Let x be the distance covered by the tip of the minute hand in 40 minutes.

$$\dfrac{x}{3\pi\ }=\dfrac{40}{60}$$

x = 2π = 6.28 cm

Therefore, the tip of the minute hand moves a distance of 6.28 cm in 40 minutes.

The answer is option A.

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