Final answer:
The original question seems to inquire about a world record set by Ken Warby, which is related to Water Skiing (D. Water Skiing). Although the question seems misplaced in the context of the given physics problem, which involves calculating velocities and times for a boat moving on a river with a current, these are classical physics problems taught at the high school level.
Step-by-step explanation:
The student is asking a question about a world record set on water by Ken Warby on October 8, 1975. However, the question seems to be part of a broader Physics problem. The details given in the reference information indicate that the question involves calculations based on velocities and times, factors that are crucial in solving physics problems related to motion. For instance, to calculate how much time is required to row downstream or upstream, we would use principles from physics to add or subtract the speed of the river to the speed of the boat in still water. Additionally, to determine in what direction the boat must be aimed and the boat's velocity with respect to Earth, we use vector analysis, which is a topic in physics.
The correct answer to the world record question is: D. Water Skiing. Ken Warby set the world record for the fastest speed on water, which relates to Water Skiing, in 1975.
The secondary series of questions a)-e) are physics problems that explore concepts of relative velocity and the effect of currents on boat movement. To solve these, students would apply kinematic equations and vector mathematics, both of which are significant topics in high school physics courses.