How far will the tip of a 2 cm-long minute hand of a clock move in 45 minutes?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 3π cm.
Given:
The minute hand of a watch is 2 cm long.
Formula Used:
Arc length, l = r × θ ----- (1)
Where l = arc length, r = radius, θ = central angle in radian
Calculation:
We know that, 1° = πc/180
Angle covered by the minute hand in 60 min = (2π)c
Angle covered by the minute hand in 45 min = (2π/60 × 45)c = (3π/2)c
Using equation (1), we get
⇒ l = 2 × 3π/2
⇒ l = 3 π
⇒ l = 3 × 3.14 = 9.42