The correct option is (c).
Explanation
In mechanics, the concepts of rest and motion are not absolute but relative. They depend entirely on the frame of reference (the observer) from which the object is being viewed.- Statement 1 is Correct: Motion is defined as a change in position of an object with respect to time and a reference point. Since the position is measured relative to an observer, motion is inherently relative. There is no absolute motion in classical physics.
- Statement 2 is Incorrect: An object can be at rest and in motion simultaneously with respect to different observers. For instance, a passenger sitting in a moving train is at rest relative to a co-passenger but is in motion relative to a person standing on the platform. This confirms that the state of rest or motion is subjective to the observer's frame of reference.
- Statement 3 is Correct: We do not feel the Earth's motion (rotation or revolution) directly because we, along with the atmosphere and surroundings, move at the same constant velocity. The Earth's motion is inferred from observations such as the apparent movement of the sun and stars, the cycle of day and night, and the changing seasons.
Key Takeaway: Rest and motion are relative terms; the same object can be stationary for one observer and moving for another, depending on their respective frames of reference.