At a speed of 15 revolutions per min.,how long will it take a wheel of radius 14 in.,rolling on its edge to travel 440 ft.

Answer 1

one rotation = 2πr = 28π inches
= 28π/12 or 7π/3 ft or appr 7.33 ft
number of rotations to go 440 ft
= 440 ÷ (7π/3) = 1320/(7π) or appr 60.024 rotations

time at 15 rotations per min
= (1320/(7π)) / 15
= 4 minutes

Answer 2

Where did the 12 come from?