Final answer:
In Physics, a spring scale measures force according to Newton's second law, with the tension equal to the weight of the mass supported (T = w = mg). If disregarding other forces and assuming equal stiffness, the tension read by the scale is the same for equal weights (Tension in Case A = Tension in Case B). Option C is correct.
Step-by-step explanation:
The subject of the question is Physics, and it pertains to understanding how a spring scale measures force. According to Newton's second law, the tension in the spring scale equals the weight of the supported mass, which means T = w = mg, where T is the tension, w is the weight, and mg represents the mass times the acceleration due to gravity.
When comparing two different cases (A and B) on a spring scale, the reading of the scale will depend on the weight of the object being measured. In general, if both springs are equally stiff and disregarding any acceleration, both springs will have equal extension if they support equivalent weights.
This is because the force exerted by the spring (Frestore) is proportional to the distance it is stretched (Δx), as stated by Hooke's Law. Therefore, if we only consider the static weight of the objects attached, the tension in both cases would be equal: Tension in Case A = Tension in Case B.
However, if there are other forces in play, such as acceleration or additional weights, the tension would vary accordingly. For example, in an elevator ascending with acceleration, the scale would read a value greater than the static weight due to the additional force required to accelerate the mass.