Vertically Projected Body
ACCELERATION DUE TO GRAVITY(G)
The uniform acceleration of a freely falling y towards the centre of earth due to earth's gravitational force is called acceleration due to gravity.
i)It is denoted by 'g'
ii)Its value is constant for all bodies at a given place. It is independent of size, shape, material, constitution (hollow or solid), nature of the body. If air resistance is ignored, all the bodies as light as a feather to a heavy metal sphere, dropped simultaneously from the same height hit the floor at the same time because all the bodies have same acceleration due to gravity.
iii)Its value changes from place to place on the surface of the earth.
iv)It has maximum (greatest) value at the poles of the earth. The value is nearly 9.83\(
m/s^2
\) .
It has minimum (least) value at the equator of the earth. The value is nearly 9.78 \(
m/s^2
\).
v)The average value of g on earth's surface is 9.8\(
m/s^2
\) .
vi)The acceleration due to gravity of a body is always directed downwards towards the centre of the earth, whether a body is projected upwards or downwards.
vii)When a body is falling towards the earth, its velocity increases, g is positive.
vii)When a body is projected upwards, its velocity decreases, g is negative.
ix)The acceleration due to gravity at the centre of earth is zero.