Final answer:
A vessel that cannot maneuver as required due to exceptional circumstances is called a disabled vessel. In a physics problem, forces on such a vessel by tugboats can be represented in a free-body diagram, which includes only the tugboats' forces if no friction or drag is present.
Step-by-step explanation:
A vessel that is unable to maneuver as required by the rules due to exceptional circumstances is referred to as a disabled vessel. In the context of a physics problem involving such a vessel, the forces exerted on it by tugboats can be analyzed using a free-body diagram. A free-body diagram is a visual representation used to illustrate all the forces acting upon an object, in this case, the vessel.
(a) To draw a free-body diagram for the disabled vessel, you would illustrate the vessel as a point and then draw vectors (arrows) starting at that point to represent the forces. The forces would be the pulls from the two tugboats. If there are no other external forces such as friction or drag, then only the forces exerted by the tugboats will be included.
(b) In drawing the free-body diagram, you should include all the forces acting on the vessel in the overhead view. However, since the problem states to assume no friction or drag forces affect the vessel, these forces are not present in the free-body diagram. If they were present, they would certainly need to be included because they would affect the vessel's motion and the result of the exerted forces.