Untitled

In the above 'movie' you can drag the blue indicator bar horizontally back and forth. The number given in the upper left hand corner is the Voltage (Volts) at the location. You can choose the green charge (above) but the red and blue charge are unknown and it is your 'job' to determine them. This can be done mathematically or you can do it experimentally if you are clever enough. Note: after choosing the value for the green charge, to set the charge values for the blue and green charges, click on them. Do it now! All charges are in microcoulombs and are in the range -10 to 10 with no decimal places ( i.e., -10, -9, -8, ... 10).

When you think you know the answers

enter them below
- and then
click the GradeIt button.

The electric potential outside of a charge (given in microcoulombs) is given by

V= 9000*Q/Dx
where
Dx
is the distance from the center of a charge to the position x where the voltage is measured. Note: You cannot measure the voltage inside the charge!

Thus the voltage from the 3 charges is given by

V= 9000*Q/Dx where Dx is the distance from the center of a charge to the position x where the voltage is measured. Note: You cannot measure the voltage inside the charge!

V= 9000*Q1/Dx1 + 9000*Q2/Dx2 + 9000*Q3/Dx3

V= 9000*Q/Dx
where
Dx
is the distance from the center of a charge to the position x where the voltage is measured. Note: You cannot measure the voltage inside the charge!

V= 9000Q₁/Dx₁ + 9000Q₂/Dx₂ + 9000*Q₃/Dx₃