the charge on a pith ball was measured as +40 nC. if the charge on an electron is -1.6 x 10^-19, how many electrons have been added or removed from the ball?

To determine the number of electrons that have been added or removed from the pith ball, we need to find the ratio between the magnitudes of the measured charge on the pith ball and the charge of a single electron.

First, let's express the charge on the pith ball in terms of the elementary charge:

Charge on pith ball = +40 nC = +40 x 10^-9 C

Now, we can calculate the number of electrons using the following formula:

Number of electrons = (Charge on pith ball) / (Charge of a single electron)

Number of electrons = (+40 x 10^-9 C) / (-1.6 x 10^-19 C)

Number of electrons = -40 x 10^-9 C / 1.6 x 10^-19 C

Number of electrons = -40 x 10^10 / 1.6

Number of electrons = -25 x 10^10

Therefore, there have been approximately 25 x 10^10 electrons either added or removed from the pith ball. Note that the negative sign indicates the removal of electrons, while a positive sign would indicate the addition of electrons.