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Mechanics DOUBT: WORK,ENERGY,POWER

When using the energy method to write an equation and find something, how do we decide on which side of the equation must loss/gain in kinetic/potential energy be written...hope this makes sense...coz everytime i get the final answer incorrect , due to writing them in the wrong side of the equation. for example; when gain in kinetic energy must be substracted from work done, i would have added it and this results in getting the final answer incorrect :frown:
(edited 1 year ago)
Original post by Marysa.15
When using the energy method to write an equation and find something, how do we decide on which side of the equation must loss/gain in kinetic/potential energy be written...hope this makes sense


initial KE + final PE - energy lost (e.g. work done by friction against the motion) + energy added (e.g. work done by the driving force) = final KE + final PE
Reply 2
Original post by Mocha Latte
initial KE + final PE - energy lost (e.g. work done by friction against the motion) + energy added (e.g. work done by the driving force) = final KE + final PE

why is final PE added in both sides???
Reply 3
Original post by Marysa.15
why is final PE added in both sides???

I'm assuming they meant initial PE on the left-hand-side because that's the correct formula.
Reply 4
Original post by notnek
i'm assuming they meant initial pe on the left-hand-side because that's the correct formula.

thank you very much
Original post by Notnek
I'm assuming they meant initial PE on the left-hand-side because that's the correct formula.



oh yeah sorry I mistyped!

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