What is the concept of work in physical science?

[Redbelly98]

Yes.
While zero net work is done on the object, different muscles are all doing work, so you will get tired. The sum of the work done by all the muscles involved is still zero.

I'll concede this point, based on rcgldr's and Russ's posts.

 

[irradiance]

"just put it this way, just imagine when you are holding an object while you are walking that object experiences a lot of external forces acting on it and the sum of those forces or what we call the net force would be zero because the forces that are acting on it are like strings that holds up that object just like a puppet where in if you view it as a particle [spherical in shape] all the forces are well distributed in all parts of the surface area of that object. from the study of vectors, taking the sum of them all [all the vectors] would eventually result to zero."

-R. Laride

 

[phyeinstein_c]

The short answer I tell people is: doing work on an object is how we change it's kinetic energy.

Here I am talking about the total (or net) work done by the net force acting on an object. As long as the object moves while a nonzero net force acts on it, it will either speed up or slow down (have a change in its kinetic energy).

We can also talk about the work done by individual forces, even if the net force does zero work.

only oin few cases we change ke... in cases where we take even the 2-d and 3-d (rarely) in consideration, then , even the p.e changes.. and the change is represented as a func of displacement (s) or instantaneous time (t) or variable force [F(t)] etc. also momentum changes.. obviously..