Message: #2  2024-10-16  

Sir Isaac Newton discovered gravitational force in 1687. The English
mathematician and physicist realized that a force was acting on
falling objects, like apples, because they wouldn't start moving from
rest otherwise. He also realized that the moon would fly off in a
straight line if some force wasn't causing it to fall toward Earth. 
Newton's Law of Universal Gravitation states that any two objects
attract each other with a force equal to the product of their masses
divided by the square of their separation. 
Newton's work, along with that of Galileo, Brahe, and Kepler, proved
that the Earth and other planets orbit the sun, not the other way
around. 
In 1798, British scientist Henry Cavendish conducted an experiment to
accurately determine the value of the gravitational constant, G. 

Message: #1  2022-07-25  

Newton's first law states that if a body is at rest or moving at a
constant speed in a straight line, it will remain at rest or keep
moving in a straight line at constant speed unless it is acted upon by
a force.

Newton's second law of motion can be formally stated as follows:

The acceleration of an object as produced by a net force is directly
proportional to the magnitude of the net force, in the same direction
as the net force, and inversely proportional to the mass of the
object.

Formally stated, Newton's third law is:

For every action, there is an equal and opposite reaction.