Final answer:
A power boat cruising at constant speed is moving with constant velocity, meaning it maintains the same speed and direction as per Newton's first law of motion and does not experience acceleration.
Step-by-step explanation:
When a power boat of mass 470 kg is cruising at a constant speed, it is not experiencing any form of acceleration, nor is it in free fall. Instead, the power boat is moving with constant velocity, which means it is moving in a straight line at a steady speed. In physics, this is described by Newton's first law of motion, which states that an object in motion will stay in motion at a constant velocity unless acted upon by an external force. The options provided suggest different states of motion, and amongst them, option C is correct since the boat remains in linear motion without changing its speed or direction.
The concept of constant velocity is crucial when analyzing the motion of a motorboat or any object. Should the boat start to decelerate, or slow down, its velocity would change over time, indicating acceleration in a direction opposite to its motion. For instance, if a motorboat traveling at a constant velocity of 5.0 m/s begins to decelerate with an acceleration of -1 m/s², it would eventually come to a stop, which is a change in velocity. Describing such motion would involve understanding the velocity function, position function, and the displacement of the boat.