Physics Problem

[Sidoh]

Note: You'll have to have an understanding (and background knowledge) on the conservation of momentum and energy in order to solve this riddle.  Try not to use the internet!

One fateful morning, a cart, which was parked at the top of a hill the night before, is found in a mangled mess along with a cart that was parked below it in the bottom of a lake. When the carts are found, the supervisor says that the engineer must have forgotten to put on the brake on the top cart.  However, the engineer still has a counter-argument!  He said that it was impossible (due to physics) that the cart could have pushed both carts (which latched on contact) over the hill and into the lake and that someone must have given it a push in order for it to have made it into the lake.

Which person is correct?

Here's a diagram with all of the necessary information:



Oh, and if you find the answer, don't make it obvious and encode it in ROT-13 or something so others can have fun figuring this out.  I really had fun solving this problem.  :)

[iago]

[rot13]Jryy, gur svefg pneg unf fbzr cbgragvny raretl. 

h = ztu = (3300)(9.8)(24) = 776160

Jura gur znff vf qbhoyrq nf gur obggbz, vg unf rabhtu raretl gb trg vg:

h = ztu
u = h/zt = 776160/((6600)(9.8)) = 776160/64680 =~ 12z

Fvapr lbhe urvtug vf 7z, lrf, vg unf rabhtu cbgragvny raretl gb trg npebff. 
[/rot13]

I'm hoping that's the right solution, I vaguely remember solving those problems all the time back in grade 12, and I think that that was the way to go :)

[Sidoh]

Assuming I used the correct mathematics to solve it, I don't think that's right.  I'll double-check with my teacher next hour and let you know, though! :)

[iago]

Assuming I used the correct mathematics to solve it, I don't think that's right.  I'll double-check with my teacher next hour and let you know, though! :)

Haha, ok.  I'm thinking that using momentum might be the key, not potential energy, although it seems like both of them should come up with the same answer. 

[Sidoh]

Haha, ok.  I'm thinking that using momentum might be the key, not potential energy, although it seems like both of them should come up with the same answer. 

I think I used both to solve it. :)

[Sidoh]

I only talked with him briefly on the matter, but it's true that momentum has to be conserved, so you have to use both the conservation of momentum and the conservation of energy to solve this problem.  If no one gets it by the time I get home, I'll formulate the answer and post it :)

By the way, since this problem was practically straight out of my book, I figured I should reference it.  It's Thomas A. Moore's "The Six Ideas That Shaped Physics".  I'd provide the page number and everything, but I don't have the book with me right now.  :)

[Sidoh]

Here's the answer!  I even did it in math type to make the matematical formulas and stuff easy to read! :)

http://www.sidoh.org/stuff/physics_problem.htm

[Towelie]

ugh, thanks. Now I dread physics!

[Sidoh]

x86] link=topic=3798.msg39327#msg39327 date=1132291836]
ugh, thanks. Now I dread physics!

Physics is fun!

You should have no problem with it, man.  There is some memorization of the formulae, but it's really the concepts that are important.  I am honestly thoroughly enjoying Physics. :)

[Towelie]

Well I guess itll come easy for me, I mean im only taking pre-calculus as a sophomore ;-)

[Sidoh]

x86] link=topic=3798.msg39334#msg39334 date=1132292237]
Well I guess itll come easy for me, I mean im only taking pre-calculus as a sophomore ;-)

Hehe.  I'm sure it will.  Subjects are truely easy when you enjoy doing them, I think.  :)

[iago]

Yeah, that kind of problem was common and easy when I was in highschool.  But that was nearly 5 years ago, so.. :-o