just physics

[justin1987]

hi everybody! i'm new here and i just learned how to post messages.
well, i happen to be pretty good in this subject and i am rather fond of it. i'm a class 10 student , so, the question i'm posting is for 10th standard students only. let's see if anyone can answer this:

consider a body at a certain hieght , say, 20
metres. at that hieght , the mechanical energy possessed by the body is x joule. the potential energy is y joule and the kinetic energy is z joule.
we know let this body fall down. when it comes to a hieght of 10 metres, let the mechanical energy of the body be p joules. let the potential energy be q joules and the kinetic energy be r joules.

now the question is, find the relation between x and p y and q z and r and give a reason for your answer.

[Paraphon]

Not good in physics, but as far I remember energy is weight times distance Kg*m. Is that body moving? If not, then the kinetic energy equals zero. Possessed energy different from potential energy? What's the definition of possessed and potential energy? At the height of 10 meters, the energy of the body will be half as of the height 20 and if the body doesn't move, than the kinetic energy is again zero. Sorry for my weak attempt .

[justin1987]

sorry, but you couldnt find the relation as wanted.
you tried, though.
anygody else would like to have a go at it?

[Paraphon]

I'm dieing for the solution. You've tortured me enough.

[Edited by Paraphon on 21st December 2003 at 20:38]

[always_alone]

i think that
x=p because mechanical energy is cte.
r-z=y-q because patiential energy in 10 meters
is less than in 20 meter and we can say that
this energy(y-q) convert to kinetic energy
then we have r-z=y-q

[justin1987]

not quite the right answer, but quite close. look, try again. here's a clue. mechanical energy remains constant.

[hellotoyou]

Oh, come on guys, what kind of class of physics have you followed... that's a shame.