The problem involves understanding the path of a pencil moving on a rotating cylindrical surface, which is then unrolled to form a flat paper. Here are the steps to determine the correct graph representation:
- The paper cylinder makes 1 revolution every 60 seconds. In our problem, the timeline is divided into three stages:
- From T1 to T2, the pencil moves for 10 seconds.
- The pencil then stops moving for the next 10 seconds.
- Finally, it moves to T3 over 40 seconds.
- In the first 10 seconds, since the pencil is moving and the cylinder is rotating, the path on the unrolled paper is a diagonal line.
- For the next 10 seconds, the cylinder continues to rotate while the pencil remains stationary, resulting in a horizontal line on the unrolled paper.
- During the final 40 seconds, the pencil moves as the cylinder rotates, again creating a diagonal path.
Considering these steps, the unrolled rectangular paper will depict the pencil path as two diagonal segments separated by a horizontal segment. Thus, the correct representation of the graph on unrolled paper is:
