Question

an object thrown at certain angle to ground moves in a curved path and falls back to the ground. the initial and final points of the path of object lie on the same horizontal line. what is the net work done by force of gravity on the object

Answer 1

Work done due to gravitational force depends only upon vertical displacement and the vertical displacement of the object is given as the difference of the initial and final position of the object which is zero in this case because the object gets back to its initial position (ground) after projection to some height. Therefore work done will be given as,
$W=mgh$
Since, vertical displacement (height) is zero therefore we get,
$W=0Joule$