Question

A barrel shaped like a cylinder is laid on its side and rolled up a ramp that is

Answer 1

$\bf r=\cfrac{s}{\theta}\qquad \begin{cases} r=radius\\ s=\textit{arc's length}\\ \theta=\textit{central angle in radians}\\ ----------\\ s=180\\ \theta=\textit{45 revolutions}\\ \qquad 2\pi \cdot 45\\ \qquad 90\pi \end{cases}\implies \begin{array}{llll} r=\cfrac{180}{90\pi }\\\\ r=\cfrac{2}{\pi }\\\\ diameter=2r\\\\ diameter=\cfrac{4}{\pi } \end{array}$