Final answer:
Detecting a vertical imbalance difference greater than 1mm becomes less precise as the unit of weight increases. Smaller weight differences are more easily perceived when the overall weight is lower, following Weber's Law.
Step-by-step explanation:
If the vertical imbalance difference is greater than 1mm, it implies that the sensitivity to perceive changes in weights or balance gets significantly reduced as the weight units increase. For example, detecting a difference between 1 and 2 units of weight is usually easier than identifying a difference between 20 and 21 units because the percentage change is much larger in the first case than in the second. It's similar to noting that a difference between 1 and 2 units is more noticeable than a difference between 2 and 4 units.
This phenomenon can be attributed to the psychophysical concept known as Weber's Law, which suggests that the noticeable difference between two stimuli is proportional to the magnitude of the stimuli. Weber's Law explains why smaller increments are more distinguishable at a lower range compared to the same incremental change at a higher range of units.