Soham answered this
First, both work and energy are expressed in the same units, wihich in the SI system is the joule. The joule breaks down to the unit of force (in SI the newton) applied along a unit of distance (in SI the meter).
This unit really defines what work is. Work is a force that is sufficient to effect movement of some object across a linear distance. This means for work to occur there must be resistance. If the object could be moved with any force due to lack of any friction or other resistances, then any movement of the object is not work.
Work is done mechanically, through physical movement and against physical resistances. When you push a lever to pry something, you are doing work to the level handle, and it is doing work to the thing you?re prying (hopefully). When a compressor?s blades or screws push a volume of gas and, over some distance, exert force that pressurizes it and changes its velocity, work has been done. When a pump impeller does the same thing to liquid, work is done.
Mechanical energy is energy applied to something via work. For example, the pressure added to the compressed gas thanks to mechanical energy can now be used to transfer that energy by doing work elsewhere (perhaps by pressurizing an actuator to turn a valve). Or, that energy can be transferred in the form of heat (if, for instance, steam was compressed) through condensation in a heat exchanger.
That last one is NOT work. It did not meet the definition of applying a resisted force over a distance. That was instead thermal energy transference. So, as we can see, while work translates into energy that energy may be used for things other than work.
So, all work imparts energy, but not all energy imparts work. Work refers to the mechanical side of things, and energy can refer to the mechanical, chemical, electrical, thermal, you name it.
Just keep in mind the definition of work and you?ll be able to spot where in a physical system it?s transpiring and where another form of energy transference is instead occurring.
Hope that helps!
This unit really defines what work is. Work is a force that is sufficient to effect movement of some object across a linear distance. This means for work to occur there must be resistance. If the object could be moved with any force due to lack of any friction or other resistances, then any movement of the object is not work.
Work is done mechanically, through physical movement and against physical resistances. When you push a lever to pry something, you are doing work to the level handle, and it is doing work to the thing you?re prying (hopefully). When a compressor?s blades or screws push a volume of gas and, over some distance, exert force that pressurizes it and changes its velocity, work has been done. When a pump impeller does the same thing to liquid, work is done.
Mechanical energy is energy applied to something via work. For example, the pressure added to the compressed gas thanks to mechanical energy can now be used to transfer that energy by doing work elsewhere (perhaps by pressurizing an actuator to turn a valve). Or, that energy can be transferred in the form of heat (if, for instance, steam was compressed) through condensation in a heat exchanger.
That last one is NOT work. It did not meet the definition of applying a resisted force over a distance. That was instead thermal energy transference. So, as we can see, while work translates into energy that energy may be used for things other than work.
So, all work imparts energy, but not all energy imparts work. Work refers to the mechanical side of things, and energy can refer to the mechanical, chemical, electrical, thermal, you name it.
Just keep in mind the definition of work and you?ll be able to spot where in a physical system it?s transpiring and where another form of energy transference is instead occurring.
Hope that helps!
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