Final answer:
Newton's First Law of Motion, also known as the law of inertia, explains the tendency of an object to remain at rest or in constant velocity motion unless externally acted upon. Inertia is linked to the object's mass, with more massive objects being more difficult to change in terms of their state of motion.
Step-by-step explanation:
Newton's First Law of Motion and Inertia
The tendency of an object or athlete either to stay at rest or move continuously in a straight line at a uniform velocity is described by Newton's First Law of Motion. This principle states that a body at rest remains at rest, or if in motion, continues to move at a constant velocity unless acted upon by a net external force. This behavior is a manifestation of the property known as inertia, which is inherent to all objects and is directly related to the mass of the object.
Motion at a constant velocity, also known as uniform motion, implies that the position of an object changes at the same rate over time without acceleration. An object is either stationary or moving with a constant speed and in a linear path. This continues to be true unless an outside force causes a change in the object's state of motion. In other words, the acceleration does not change during uniform motion, as the gradient or rate of velocity remains constant.
It is important to understand that the amount of inertia an object exhibits depends on its mass. Greater mass implies greater inertia, making it more challenging to alter the object's state of rest or motion. This concept helps explain why it is harder to push a heavy boulder than it is to move a basketball.