DD.45 Carry an iron plate

As shown in the figure, cylinders with same form and same size are rolled without sliding so that they may carry an iron plate in the direction of an arrow.
A radius at the bottom of each cylinder is 15 cm and each cylinder rolls with a fixed speed and it is rotated one time in 12 seconds.
An iron plate moves without sliding on a cylinder.
The cylinder is placed so that it may not contact mutually, even when it rolls.
Answer the following questions.
Pi is assumed to be 3.14.

(1) Find the length where the cylinder moves rolling in the direction of an arrow in one second .

(2) Find the distance where an iron plate moves in the direction of an arrow in 10 seconds.




Answer
(1) 7.85 cm
(2) 157 cm