Question

Calculation Questions (2 Questions, 12 Points Each)1. Electrical charge is sometimes reported in coulombs (C). On this scale, 1 electronhas a charge of -1.6 x 10-19 C. Suppose your body acquires a -125 mC charge on adry day. How many excess electrons has it acquired?

Answer 1

Answer: 7.8125x10^-22 electrons.

Calculations:

• Let ,x , represent electron in a body.

,

• use the following formula tocalculagte excess electrons acquired.

,

• Charge = 125mC /10000 =1.25 x10^-2

`\begin{gathered} \text{Charge = electron }\cdot\text{ electron charge } \\ 1.25X10^{-2\text{ }}=\text{ x }\cdot1.6X10^(-19) \\ x\text{ = }(1.25X10^(-2))/(1.6X10^(-19)) \\ \text{ }\therefore x\text{= }7.8125X10^(-22) \end{gathered}`

This means that there are 7.8125x10^-22 excess electron aqcuired.