Gravitational Motion

Consider a Ball falling from a certain height. Now due to earth's gravitational force exerted on the ball, the ball will experience some force of attraction when it falls from a certain height. In simple terms the motion of the ball under the earth's gravitational force of attraction can be said as gravitational motion.

 Note: The weight of an object is due to Gravitational force exerted on the object.

 Consider a Vertical motion under gravity wrt one dimensional motion with constant acceleration. As we know acceleration is always directed in vertically downward direction and considers its magnitude is "g".

 All objects, irrespective of their mass, experience the same acceleration g when falling freely under the influence of gravity at the same point on the Earth. Close to the Earth's surface,

 g = 9.8 m s−2

We know that the force due to gravity may be opposite to the direction of motion;  Hence, there exists an possibility that the body under force of gravity reverses its direction. It is, therefore, very  important to understand that the quantities involved in the equations of motion may evaluate to positive or sometimes negative values with the exception of time (t).

i.e., In case the ball is dropped, the downward direction is usually taken as positive, i.e. we take the positive value of g for the acceleration.

If the ball is thrown vertically upwards, the upward direction could be chosen as positive; in this case the acceleration is -g.

We must appropriately fix sign to various inputs that goes into the equation and correctly interpret the result with reference to the assumed positive direction. Further, some of them evaluate to two values one for one direction and another of reversed direction.

Gravitation is in charge for keeping the Earth and the other planets in their Orbit. The motion of earth around sun and on its own axis is controlled by the effective gravitational forces exerted by Sun on earth and vice versa. Also in physics, an orbit is defined as the gravitationally curved path of an object around a point in space.

Consider gravity is the only force acting on an object, then the sum of kinetic energy and gravitational energy is constant. Increases in the kinetic energy are balanced by decreases in gravitational energy, and vice versa.