Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2007-03-27 02:28:53

luca-deltodesco
Member
Registered: 2006-05-05
Posts: 1,470

mech2 problems

im having some problems getting my head around the whole work done priniciple:

i understand that its the resolved part of the force in the direction of movement times the distance moved, but i dont get how this relates to kinetic energy.

for example, in some of the questions its state that an object moves from rest, to rest, over a distance of 5m, so that means the change in kinetic energy is 0, so work done is 0, but quite clearly by the first defintion its not 0...


The Beginning Of All Things To End.
The End Of All Things To Come.

Offline

#2 2007-03-27 02:41:15

Stanley_Marsh
Member
Registered: 2006-12-13
Posts: 345

Re: mech2 problems

You must be confused by this equality

.  that F is the combination of all forces
Your example is an object move from rest to rest.  If you pull the object , it will move  ,, the kinetic energy increases with the work you done , but careful , you have to subtract the work that friction done as well . the object from rest to rest , indicates that the work friction has done is equal to the work you have done.


Numbers are the essence of the Universe

Offline

#3 2007-03-27 04:21:35

luca-deltodesco
Member
Registered: 2006-05-05
Posts: 1,470

Re: mech2 problems

ah, that makes sense now.


The Beginning Of All Things To End.
The End Of All Things To Come.

Offline

Board footer

Powered by FluxBB