1. Understand Coulomb's Law

Coulomb's Law describes the electrostatic force between two charged objects:

* F = k * (q1 * q2) / r²

Where:

* F is the force between the charges (in Newtons)

* k is Coulomb's constant (approximately 8.98755 × 10⁹ N⋅m²/C²)

* q1 and q2 are the magnitudes of the charges (in Coulombs)

* r is the distance between the centers of the charges (in meters)

2. Set Up the Equation

Since the spheres have identical charges, we can simplify the equation:

* F = k * (q²) / r²

3. Convert Units

* Convert the distance from centimeters to meters: 75 cm = 0.75 m

4. Solve for the Charge (q)

* Rearrange the equation to solve for 'q':

* q² = (F * r²) / k

* q = √((F * r²) / k)

* Plug in the values:

* q = √((0.30 N * (0.75 m)²) / (8.98755 × 10⁹ N⋅m²/C²))

* Calculate the result:

* q ≈ 1.77 × 10⁻⁶ C

Answer

The magnitude of the charge on each sphere is approximately 1.77 × 10⁻⁶ Coulombs (or 1.77 micro Coulombs).