The motion of freely falling bodies:

          The acceleration of freely falling bodies is called gravitational acceleration.

It is denoted by g. On the surface of the Earth, its value is approximately 10 ms^-2.

            For bodies falling freely, g is positive and is negative for bodies moving up.

            Galileo was the first scientist to notice that all the freely falling objects have the same acceleration independent of their masses. He dropped various objects of different masses from the leaning tower of Pisa. He found that all of them reach the ground at the same time.