Question

an object thrown at a certain
angle to the ground moving in the curved path and follows back to the ground initial and the final point of the path of object lies on the same horizontal line what is the work done by the force of gravity on object?

Answer 1

Because there is no displacement in the vertical plane, the work done by gravity is zero... you can also understand in the way that the work done by gravity during ascent is equal to the work done during descent and is equal to it...
$w_{descent} = - w_{ascent}$