Three point charges q, 2q and 8q are to be placed on a
. 9cm long straight line. Find the
. positions where the charges shouldbe placed such that the potential energy
. of this sysrem is minimum. In this situation, what is the
. electric field at the charge q due to the other two charges?

Explanation

To solve the problem of placing three point charges \( q \), \( 2q \), and \( 8q \) on a 9 cm long straight line such that the potential energy of the system is minimized, we can follow these steps:

### Step 1: Understanding the Configuration
We have three charges:
- Charge \( q \) (let's denote it as \( Q \))
- Charge \( 2q \) (denote it as \( 2Q \))
- Charge \( 8q \) (denote it as \( 8Q \))

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