Question

Suppose that a blindfolded person is holding 10 pennies in one hand and that 3 pennies have to be added before the person reports that the pennies feel heavier. According to Weber's law, how many pennies would have to be added to get a just-noticeable difference if the person were holding 50 pennies?

Answer 1

Answer:
To get a just-noticeable difference (JND) when holding 50 pennies, you would need to add 15 pennies according to Weber's law.

Explanation:
According to Weber's law, the just-noticeable difference (JND) in stimulus intensity is a constant proportion of the initial stimulus intensity. In mathematical terms:

JND = k * I

Where:

JND is the just-noticeable difference.

k is Weber's constant (a constant proportionality factor).

I is the initial stimulus intensity.

In this case, you have 10 pennies as the initial stimulus intensity (I), and you want to find out how many pennies (ΔI) need to be added to get a JND when holding 50 pennies (new stimulus intensity). We can set up the equation as follows:

JND = k * I

ΔI = k * I

To find k, we can use the information given that 3 pennies need to be added to make a noticeable difference when starting with 10 pennies. So:

3 = k * 10

Now, solve for k:

k = 3 / 10

k = 0.3

Now that we have the value of k, we can use it to find out how many pennies (ΔI) need to be added to get a JND when holding 50 pennies:

ΔI = k * 50

ΔI = 0.3 * 50

ΔI = 15

So, according to Weber's law, you would need to add 15 pennies to the initial 50 pennies to get a just-noticeable difference when holding 50 pennies.