Question

define positive and negative work give SI unit of work

Answer 1

work done by a force is positive if the applied force has a component in direction of displacement,e.g. when a object is falling down , gravitational force is acting downwards,it's positive work

if the force has a component in the direction opposite to the displacement, it's negative work,e.g. when a object is made to slide frictional force is opposition it's direction of displacement, it's negative work

SI unit of work is joule (J ) which is defined as the work expended by a force of one Newton through a displacement of one metre..


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