Question

Ques 13 a), b)
Q13) (a) An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?
(b) A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer

Answer 1

Dear Student ,
13.(a)Here in this case the work done by the force of gravity on the object depends only on vertical displacement .Vertical displacement is given by the difference in the initial and final positions or heights of the object which is zero .
So the work done by the gravity is ,
W=mgh
But here vertical displacement , h = 0
So , work done , W = 0 .
Therefore work done by the gravity on the given object is zero joule .
(b) Work done by gravity depends only on the vertical displacement of the body .
It does not depend upon the path of the body .
So here vertical displacement is zero .
So , W= mgh = 0 .
Therefore work done by the gravity on the given object is zero joule .
Regards