define positive,negative and zero work with examples
Work done is positive if there is positive displacement is in direction of applied force. For e.g. if you push a cart and it moves forward.
It is negative when there is negative displacement in direction of applied force. For e.g. the work done by frictional force against a moving body.
It is zero if there is no unbalanced force applied or if there is no displacement in the direction of applied force. For e.g, when you try to move a large rock but fails.
There can be more examples in each case .