The first law- of a moving object will continue moving in a straight line at the constant speed, and a stationary object and will remain at rest, unless acted on by an unbalanced force.The second law- the acceleration produced on the body by force is proportional to the magnitude of the force and is inversely proportional to the mass of the object. Force = mass x acceleration. Third law- for every action there is an equal and opposite reaction
Newton's law of universal gravitation f= Gxm1xm2 /distance square
Between any two objects in the universe there is an attractive force (gravity) that is proportional to the masses of the objects and inversely proportional to the square of the distance between them.
weight and gravity
The gravitational attraction between you and earth would pull you down if you weren't standing on the ground. As it is, the ground exerts force equal and opposite to that of gravity, before she can fill in the souls of the feet. A scale measures that force. This case, a decisive that a counterbalance to force registers on display and you call it your weight.