How do I find the other charge using electric potential?

[moeug1999]

Homework Statement

The potential equals 7.68 V at the midpoint between two point charges that are 1.11 m apart. One of the charges is 1.06 10-9 C. Find the value of the other charge.

Relevant Equations

I assume the k|q1||q2|/r^2

I tried looking for the other charge using the equation k|q1||q2|/r^2 but it tells me that my answer is wrong

 

[berkeman]

Homework Statement:: The potential equals 7.68 V at the midpoint between two point charges that are 1.11 m apart. One of the charges is 1.06 10-9 C. Find the value of the other charge.
Relevant Equations:: I assume the k|q1||q2|/r^2

I tried looking for the other charge using the equation k|q1||q2|/r^2 but it tells me that my answer is wrong

Please show us your detailed calculation so we can check it for you. Thanks.

 

[moeug1999]

Please show us your detailed calculation so we can check it for you. Thanks.

here's my attempt

 

[kuruman]

Relevant Equations:: I assume the k|q1||q2|/r^2

What you have there is irrelevant to this problem. Not only that but it's not even an equation. Your attempt in post #3 shows a bunch of numbers without a starting equation. This problem is about the electric potential due to point charges. What is a general expression for that? That should be your starting point.