The orbit of a planet is an ellipse with the Sun at the one of the foci.The line joining the planet and the Sun sweeps equal areas in equal intervals of time.
whenever a force is acting on an object, it produces acceleration in it. The gravitational force of attraction produces acceleration both in the Earth and in the stone.
The motion of a body under gravity is a uniformly accelerated motion and hence all the equations of motion for uniformly accelerated motion along a straight line is applicable to the motion of bodies under gravity.
The density of a substance remains the same under certain specified conditions. Thus the density of a substance is one of its characteristic properties and this property can be used to determine the purity of any substance.
We have defined the force as an external agent, which changes the direction of motion, speed or shape of the body. All along we were discussing only about the forces acting at a point on a body.
