The electrostatic force on a small sphere of charge is 0.4 µC due to another small sphere of charge –0.8 µC in the air is 0.2 N. (a) What is the distance between the two spheres? (b) What is the force on the second sphere due to the first?

```html

Sure, I can help you with that.

Part (a)

We can use Coulomb's law to calculate the distance between the two spheres. The equation for Coulomb's law is:

``` ```html F = k * q1 * q2 / r^2 ``` ```html

where:

``` ```html

• F is the force between the two charges (in Newtons)
• k is Coulomb's constant (8.987551787 × 10^9 N m^2 C^-2)
• q1 and q2 are the charges of the two spheres (in Coulombs)
• r is the distance between the two spheres (in meters)

``` ```html

We know that F = 0.2 N, q1 = 0.4 µC, and q2 = -0.8 µC. We can plug these values into the equation to solve for r.

``` ```html 0.2 N = 8.987551787 × 10^9 N m^2 C^-2 * (0.4 µC) * (-0.8 µC) / r^2 ``` ```html

r^2 = (8.987551787 × 10^9 N m^2 C^-2 * (0.4 µC) * (-0.8 µC)) / 0.2 N

``` ```html

r^2 = 11.5604 × 10^-11 m^2

``` ```html

r = 1.071 m

``` ```html

Part (b)

The force on the second sphere due to the first is equal in magnitude but opposite in direction to the force on the first sphere due to the second. Therefore, the force on the second sphere is also 0.2 N. However, the direction of the force on the second sphere is towards the first sphere, while the direction of the force on the first sphere is away from the second sphere.

I hope this helps! Let me know if you have any other questions.

``` This is just a basic example of how to convert text into HTML code. You can use this code as a starting point, and then modify it to suit your needs.