What does "Work done on the object" mean

[duoheer]

what is the difference between "work done on the object" and "work done by the net force"? if there is a difference, can u give me an example? thanks thx

 

[lightgrav]

"Work done on the object" is a general phrase ;
the source Force can be specified (as, "W on object by friction Force"),
they can be a subset of Forces ("total W by all the conservative Forces") (=PE's),
they can be the entire set of all Forces applied to the object.
The object can be a system composed of multiple parts, with the parts
able to Exchange Energy with another part.
The approach introduced by this phrase can be extended to treat thermal Energy transfer.

Here, the source Force might *by implication* be a Force that has been
the focus of the last paragraph or two.

"Work done by the net Force" is a lousy phrase ;
it rewards students who do not distinguish cause (Forces, with sources)
from effect (ma).
It avoids mention of the most important item of the process (the OBJECT which Force is applied to...). It is always equal to the change in the (implied) object's KE, so it is at best a riddle-name for d KE.

 

[quicknote]

Work done on an object refers to the amount of energy transferred to the object by an external force. This can result in a change in the object's velocity, position, or internal energy. On the other hand, work done by the net force refers to the total amount of energy transferred to an object by all the forces acting on it.

There is a difference between these two concepts because work done on an object can be positive or negative, depending on the direction of the force and the displacement of the object. For example, if you push a box across the room, the work done on the box is positive because the force and displacement are in the same direction. However, if you pull the box back towards you, the work done on the box is negative because the force and displacement are in opposite directions.

On the other hand, work done by the net force is always positive because it takes into account the total energy transferred to the object by all the forces acting on it. In the example above, the work done by the net force on the box would be positive regardless of whether you pushed or pulled the box, as both actions result in a change in the object's velocity.

In summary, work done on an object and work done by the net force are related concepts, but they are not the same. Work done on an object is specific to a single force acting on the object, while work done by the net force takes into account all the forces acting on the object.