A base unit (also referred to as a fundamental unit) is a unit adopted for measurement of a base quantity. A base quantity is one of a conventionally chosen subset of physical quantities, where no quantity in the subset can be expressed in terms of the others. The International System of Units (SI), commonly known as the metric system, is the international standard for measurement. ... The SI is made up of 7 base units that define the 22 derived units with special names and symbols. The units and their physical quantities are the second for time, the metre for measurement of length, the kilogram for mass, the ampere for electric current, the kelvin for temperature, the mole for amount of substance, and the candela for luminous intensity. The various features and future prospects of the International System of Units (SI) are described. The SI is based on seven selected base units, corresponding to the seven quantities such as length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity. Units are of two types: Fundamental units. Derived units. or powering the base units in various combinations, For example: mechanical work is force applied multiplied by distance moved and has the unit newton metre written as Nm. speed is distance divided by time and has the unit metre per second written as ms. The three measures are descriptive, diagnostic, and predictive. Descriptive is the most basic form of measurement.
I would say that this passage is an example of the heliocentric correct view of the world with the sun and not the earth the center of our universe and this formed a very important part of the Renaissance wherein nature was examined first hand wherever possible to arrive at a much closer approximation of the truth than in Medieval or Classical times of Aristotle when idle speculation about nature was the order of the day.
The force between two system is inversely proportional to the square the distance between them. The indirect proportion between these items may be expressed as, F = k / d² where k is the constant proportionality. Substituting the known values, 0.68 N = k / (1 m)² ; k = 0.68 For the second case, F = 0.68 / (0.5 m)² = 2.72 N Thus, the answer is 2.72 N.
