Grade 11Mechanics
If work done is a scalar,how can it be negative???
If work done is a scalar,how can it be negative???
4 Answers
Carmel Emmanuel
Though work is a scalar quantity but the sign is used to tell significance of energy gained or lost by a system. if work done is positive system gains energy if work done negative the system loses its energy.
Suppose you stop a moving body already in motion. You apply a force opposite to the direction of motion of the body so work done by you in this process is negative and the body comes at rest. The body has lost its kinetic energy due to negative work done by you on the body. So negative work only denotes loss of energy.
Gopikrishnan
How can you say that energy is gained or lost?
It is a basic postulate that enegy can neither be gained nor lost...
Carmel Emmanuel
Approved Tutor Answer10 Years agoThis postulate does not mean that energy from a body does not lose. Energy is lost in surroundings but may change into another form. Total energy of Universe remain constant. Further mechanical energy of body remains conserved if no non conservative or external force acts on it.
Mondo Camry
work is not negative, we assume it negative for the opposite direct
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