Final answer:
A reference point enables people to compare relative motion as it provides a frame of reference. This concept is ingrained in physics for describing motion and understanding that speed affects measurements of time and space from different perspectives.
Step-by-step explanation:
A reference point is crucial in determining the motion of an object. It allows people to compare relative motion, which is the change in position of one object in relation to another object. The concept of relative motion is fundamental in physics, especially when considering how motion might appear differently from various reference frames.
Using a reference point, one can establish a frame of reference, which is an arbitrarily fixed point with respect to which the motion of other points is measured. According to Essential Knowledge 3.A.1, within a given reference frame, an observer can describe the motion of an object using several quantities, which include position, displacement, distance, velocity, speed, and acceleration.
A reference point can help people: D) Compare relative motion rather than making absolute speed calculations or measuring time more accurately. Relative speed is the distance divided by elapsed time and must be consistent across different observers' frames of reference, regardless of their varying measurements of time and space.