4: Suppose you have a large spool used for winding rope (just like a spool of thread), such as the one shown in Figure 12.69. Suppose that the spool is 1 m long and has an inner diameter of 20 cm and an outer diameter of 60 cm. Approximately how long a piece of 5-cm-thick rope can be wound onto this spool? (Assume that the rope is wound on neatly, in layers. Each layer will consist of a row of “winds,” and each “wind” will be approximately a circle.) Explain your reasoning.