""" Title : Finding the value of either Gravitational Force, one of the masses or distance provided that the other three parameters are given. Description : Newton's Law of Universal Gravitation explains the presence of force of attraction between bodies having a definite mass situated at a distance. It is usually stated as that, every particle attracts every other particle in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. The publication of the theory has become known as the "first great unification", as it marked the unification of the previously described phenomena of gravity on Earth with known astronomical behaviors. The equation for the universal gravitation is as follows: F = (G * mass_1 * mass_2) / (distance)^2 Source : - https://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation - Newton (1687) "PhilosophiƦ Naturalis Principia Mathematica" """ from __future__ import annotations # Define the Gravitational Constant G and the function GRAVITATIONAL_CONSTANT = 6.6743e-11 # unit of G : m^3 * kg^-1 * s^-2 def gravitational_law( force: float, mass_1: float, mass_2: float, distance: float ) -> dict[str, float]: """ Input Parameters ---------------- force : magnitude in Newtons mass_1 : mass in Kilograms mass_2 : mass in Kilograms distance : distance in Meters Returns ------- result : dict name, value pair of the parameter having Zero as it's value Returns the value of one of the parameters specified as 0, provided the values of other parameters are given. >>> gravitational_law(force=0, mass_1=5, mass_2=10, distance=20) {'force': 8.342875e-12} >>> gravitational_law(force=7367.382, mass_1=0, mass_2=74, distance=3048) {'mass_1': 1.385816317292268e+19} >>> gravitational_law(force=36337.283, mass_1=0, mass_2=0, distance=35584) Traceback (most recent call last): ... ValueError: One and only one argument must be 0 >>> gravitational_law(force=36337.283, mass_1=-674, mass_2=0, distance=35584) Traceback (most recent call last): ... ValueError: Mass can not be negative >>> gravitational_law(force=-847938e12, mass_1=674, mass_2=0, distance=9374) Traceback (most recent call last): ... ValueError: Gravitational force can not be negative """ product_of_mass = mass_1 * mass_2 if (force, mass_1, mass_2, distance).count(0) != 1: raise ValueError("One and only one argument must be 0") if force < 0: raise ValueError("Gravitational force can not be negative") if distance < 0: raise ValueError("Distance can not be negative") if mass_1 < 0 or mass_2 < 0: raise ValueError("Mass can not be negative") if force == 0: force = GRAVITATIONAL_CONSTANT * product_of_mass / (distance**2) return {"force": force} elif mass_1 == 0: mass_1 = (force) * (distance**2) / (GRAVITATIONAL_CONSTANT * mass_2) return {"mass_1": mass_1} elif mass_2 == 0: mass_2 = (force) * (distance**2) / (GRAVITATIONAL_CONSTANT * mass_1) return {"mass_2": mass_2} elif distance == 0: distance = (GRAVITATIONAL_CONSTANT * product_of_mass / (force)) ** 0.5 return {"distance": distance} raise ValueError("One and only one argument must be 0") # Run doctest if __name__ == "__main__": import doctest doctest.testmod()