Answers

2014-11-09T13:11:23+05:30
HERE 
THE WORK IS DONE AGAINST THE GRAVITATIONAL FORCE SO THE WORK DONE MUST BE NEGATIVE
THEREFORE
IF WE THROW A BALL UP IN THE AIR THEN THE WORK DONE IS NEGATIVE
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it is against gravitational force
again,if the ball returns to the original position,the work done is 0.am i right??
yes u r right the work done will be 0 if the ball returns to its original position it is so because displacement will be 0
work done by the man is positive and that becomes initial kinetic energy. Work done by the gravity force is negative when ball goes up in the direction opposite to force.. Work done by gravity is positive as the ball comes down as ball moves in the same direction as force.
2014-11-09T13:15:06+05:30
The answer is negative this a question in our science book and i know that it is negative
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