Answer:
4π in ≈ 12.57 in
Step-by-step explanation:
One full revolution (2π radians) is made in 60 minutes. In 40 minutes, the hand moves through an angle θ of (40/60)(2π) = 4π/3 radians. The length of the arc is ...
s = rθ = (3 in)(4π/3) = 4π in ≈ 12.57 in