Which one of these is true? (A) Motion is relative (B) Motion is not relative (C) Something is not in motion if its position with respect to the observer changes with time. (D) Both (A) and (B)
Answer (1)
To understand which statement about motion is true, let's first explore what motion means in physics. Motion is the change in the position of an object with respect to time. Importantly, motion is always described relative to a frame of reference.
Option A: Motion is relative.
This statement is true. Motion being 'relative' means that whether an object is considered to be in motion or at rest depends on the observer's frame of reference. For example, a person sitting in a moving car is at rest relative to the car but is in motion relative to the ground.
Option B: Motion is not relative.
This statement is false. The concept of relativity is fundamental to understanding motion, meaning motion can only be described relative to a particular frame of reference.
Option C: Something is not in motion if its position with respect to the observer changes with time.
This statement is incorrect. If an object's position changes with respect to an observer over time, it means the object is in motion relative to that observer.
Option D: Both (A) and (B).
This option cannot be true because option B is incorrect.
In conclusion, the correct answer is option A: Motion is relative. This concept is based on the principles of classical mechanics, which describe objects in everyday situations.
