Final answer:
The gravitational force between the two stars in a binary system is calculated using the masses of the stars, their separation, and the gravitational constant by applying Newton's law of universal gravitation.
Step-by-step explanation:
The gravitational force between two stars in a binary star system is calculated using Newton's law of universal gravitation. Given the masses of the stars are 2.0×10³° kg and 6.3×10³° kg, and their separation is 1.8×10¹² m, we apply the formula:
F = G × (M₁ × M₂) / R²,
where F is the gravitational force, G is the gravitational constant (6.67×10⁻¹¹ Nm²/kg²), M₁ and M₂ are the masses of the two bodies, and R is their separation. Plugging in the values:
F = 6.67×10⁻¹¹ × (2.0×10³° kg × 6.3×10³° kg) / (1.8×10¹² m)²
Note: The above expression should be computed using a calculator to obtain the numerical value of the force in newtons (N).