What does Weber's Law about 'just noticeable differences' predict about how much someone has to change the brightness of a light before we can notice the difference? a. It depends on how bright the light was in the first place - the brighter it was, the less change is needed before we realize it. b. It depends on how long we have been looking at the light - the longer we have been looking, the more change is needed. c. It is always the same amount - 7 lux. d. It depends on how bright the light was in the first place - the brighter it was, the more change is needed before we realize it.

answer A is the correct one

Explanation:

Weber's law states that  "the smallest discernible change of a stimulus and proportional to the stimulus".

Applying this law to cases of optical intensity, the ratio must be

          k = cte = ΔI / I

where ΔI is the variation of the intensity and I is the value of the intensity

In general, for humans, the constant is 0.15 for the rods and 0.015 for the cones of the retina.

When reviewing the answers, answer A is the correct one, since in order for the previous relationship to be maintained, the magnitudes must rise proportionally

the binding energy is the energy required to create z separate protons and n=a-z separate neutrons from a (a,z) nucleus in its ground state. another way to think about it is binding energy is the mass energy which is missing from a nucleus compared to the mass energy of the individual nucleons.