Sunday 25 March 2018

newtonian mechanics - Why does work depend on distance?


So the formula for work is$$ \left[\text{work}\right] ~=~ \left[\text{force}\right] \, \times \, \left[\text{distance}\right] \,. $$


I'm trying to get an understanding of how this represents energy.


If I'm in a vacuum, and I push a block with a force of $1 \, \mathrm{N},$ it will move forwards infinitely. So as long as I wait long enough, the distance will keep increasing. This seems to imply that the longer I wait, the more work (energy) has been applied to the block.


I must be missing something, but I can't really pinpoint what it is.


It only really seems to make sense when I think of the opposite scenario: when slowing down a block that is (initially) going at a constant speed.



Answer



You have to put in the distance on which the force acts. If you release the force, there will be no work done since there is no force acting on the body.


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