State the three equations of motion of a body under the influence of gravitational force of earth. When is g positive and when is it negative? What is maximum height?

Explanation

The three equation of motion of body under the infulece of gravitational force of earth are
(i) `v=u+g t`
(ii) `s=ut+(1)/(2)g t^(2)` (iii) `v^(2)-u^(2)=2gs`
the value of g is positive when body is falling freely towards earth, and the value of g is negative when a body is thrown up vertically. maximum height is the height at which up ward velocity (of projection) of the body reduce to zero.