how does the value of g becomes negative and positive.why is it not always negative or always positive?

Dear student

Using cartesian conventions, g is always taken as negative irrespective of the direction of motion of a body with respect to ground.

 

g is directed along the gravitational force which is directed towards the center of earth. According to cartesian conventions, since g is directed along - y axis, it is always taken as negative.

 

We hope that clarifies your query.

 

Regards

Team

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