Which of the following best describes a reference frame in physics?

• A. A force that acts only at a distance
• B. A coordinate system or viewpoint from which measurements of $\mathrm{position}$, $\mathrm{velocity}$, and $\mathrm{acceleration}$ are made
• C. A device used to measure the mass of an object
• D. A material that resists changes in motion

Answer: (B)

Verified step by step guidance

1. Understand that a reference frame in physics is essentially a perspective or viewpoint from which an observer measures physical quantities like position, velocity, and acceleration.
2. Recognize that it is not a physical object or force, but rather a coordinate system that can be stationary or moving relative to other frames.
3. Recall that measurements of motion depend on the chosen reference frame, meaning the same object can have different velocities or accelerations when observed from different frames.
4. Eliminate options that describe physical forces, devices, or materials, as these do not define a reference frame.
5. Conclude that the best description of a reference frame is 'a coordinate system or viewpoint from which measurements of position, velocity, and acceleration are made.'