How far much a charge of 9 microcoulombs be to experience an electric field strength of 900000N/C ?

To calculate the distance at which a charge of 9 microcoulombs would experience an electric field strength of 900,000 N/C, we can use the formula for electric field strength:

E = k * Q / r^2

Where:
E = electric field strength (900,000 N/C)
k = Coulomb's constant (8.99 x 10^9 N m^2/C^2)
Q = charge (9 microcoulombs = 9 x 10^-6 C)
r = distance

Rearranging the formula to solve for r:

r = sqrt(k * Q / E)

Plugging in the values:

r = sqrt((8.99 x 10^9 N m^2/C^2) * (9 x 10^-6 C) / 900,000 N/C)
r = sqrt((8.09 x 10^4 m^2) / 900,000)
r = sqrt(0.0899 m^2)
r = 0.3 meters

Therefore, a charge of 9 microcoulombs would need to be 0.3 meters away to experience an electric field strength of 900,000 N/C.

The electric field strength (E) is given by:

```
E = F/q
```

Where:

- E is the electric field strength in N/C
- F is the force experienced by the charge in N
- q is the charge in Coulombs

We are given:

- E = 900000 N/C
- q = 9 microcoulombs = 9 - 10^-6 C

Substituting these values into the equation, we get:

```
900000 N/C = F / (9 - 10^-6 C)
```

Solving for F, we get:

```
F = 900000 N/C - (9 - 10^-6 C) = 8.1 N
```

Now, the force experienced by the charge is given by:

```
F = k - q1 - q2 / r^2
```

Where:

- k is the Coulomb constant (9 - 10^9 N m^2/C^2)
- q1 is the charge of the first object in Coulombs
- q2 is the charge of the second object in Coulombs
- r is the distance between the charges in meters

We are not given the charge of the second object or the distance between the charges, so we cannot calculate the distance directly. However, we can rearrange the equation to solve for r:

```
r = sqrt(k - q1 - q2 / F)
```

Substituting the given values and the value of F that we calculated, we get:

```
r = sqrt(9 - 10^9 N m^2/C^2 - (9 - 10^-6 C)^2 / 8.1 N) = 3.1 - 10^-3 m
```

Therefore, the charge must be 3.1 - 10^-3 meters away from the electric field to experience an electric field strength of 900000 N/C.