High School

An athlete notices that, after lifting a 100-kilogram weight, he has to increase the weight to 105 kilograms before he feels that the weight is actually heavier. If the athlete later lifts a 200-kilogram weight, which of the following coincides with the just noticeable difference for this weight?

A. A 190 kg weight
B. A 205 kg weight
C. A 215 kg weight
D. A 220 kg weight

Answer :

Answer:

option A

Explanation:

given,

lifting weight = 100 Kg

increase in the weight = 105 Kg

later athlete lift = 200 Kg

Weber's law states that Just noticeable difference of weight is equal to ratio of change to the original.

Just noticeable difference for weight will be

=[tex]\dfrac{105-100}{100}[/tex]

= 5 %

since second weight is 200 Kg

so, Just noticeable difference of 200 Kg will be equal to ± 5 % of 200 Kg which is equal to ± 10 Kg.

now,

Just noticeable difference for 200 Kg

= 200 + 10 or 200 -10

= 210 Kg or 190 Kg

Hence, the correct answer is option is option A