Final answer:
Waste will flow downward in a properly installed bell and spigot cast iron pipe, utilizing gravity to remove the waste from the plumbing system. The rotation of draining water is typically caused by the fixture's design, not the Coriolis effect, which is negligible in small-scale applications.
Step-by-step explanation:
When bell and spigot cast iron pipe is installed correctly, waste will flow downward, which is option b) Vertically downward in the coordinate system. Gravity ensures that waste and water flow from a higher to a lower elevation within the pipe system. This setup is crucial for the proper function of waste disposal systems in buildings, particularly in plumbing applications. The design of these systems takes advantage of gravity to move waste effectively and maintain sanitation.
Concerning the rotation of water as it goes down a drain, often referred to as the Coriolis effect, this is a very small effect that is mostly overwhelmed by the design of the sanitary fixture, such as the directional water jets in a toilet. If water were forced up a drain, the direction of rotation would not necessarily reverse because the Coriolis force is too weak to influence the water motion significantly in such small-scale scenarios.