Yesterday,after carrying groceries that weighed 5 pounds for a while,Brenda also picked up a parcel left at her door,which weighed half a pound.She immediately noticed a change in the weight of what she was carrying.If her groceries had weighed 10 pounds,the just noticeable difference with the addition of the parcel would be ________ pound(s).
A) 1
B) 2
C) 4
D) 5

Question

Quizplus · Accepted Answer

The just noticeable difference is based on Weber's Law, which states that the ratio of the increment threshold to the background intensity is a constant. Since Brenda noticed a change when the parcel was half a pound with groceries weighing 5 pounds, doubling the weight of the groceries to 10 pounds would double the just noticeable difference to 1 pound.

Yesterday,after Carrying Groceries That Weighed 5 Pounds for a While,Brenda