Could someone PLEASE get me out of misery? (1 Viewer)

[nml10]

Two objects with masses 4.40kg and 1.40kg hang 0.800m above the floor from the ends of a cord 7.60m long passing over a frictionless pulley. Both objects start from rest. Find the maximum height reached by the 1.40kg object.

THIS QUESTION HAS GOT ME STRESSING OVER THE PAST TWO DAYS! someone help me by taking me through the steps.. :'(

 

[zxreth]

SAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAME. question 8 of the mastering physics assignment right?

 

[nml10]

SAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAME. question 8 of the mastering physics assignment right?

HAHAHAHHAHAHAHAHAHAHAHAHAHAHAHAHA YEAH! it's the troll question of the week i have to say..

 

[zxreth]

have you managed to get it yet? i tried using energy and stuff, but i failed

 

[nml10]

i have used up seven out of my eight attempts but have yet found the correct solution.. did you exhaust all your eight attempts? D:

 

[zxreth]

i've used 3 of mine so far, how do your answers range like?

EDIT: just realised some of our given values are different.

 

[Ferox]

Usually someone's done the questions before

http://malaysia.answers.yahoo.com/question/index?qid=20110130060557AAAYICM

 

[nml10]

i've used 3 of mine so far, how do your answers range like?

EDIT: just realised some of our given values are different.

my answer roams around 2.0. how about you?

i did what they did but the answer comes out wrong :s but thanks Ferox

 

[Ferox]

I got 2.014

and the general formula

h_max=h₀(M-m)/(M+m)+2h₀

where h₀ is initial height, M is larger mass and m smaller mass.

 

[zxreth]

I got 2.014

and the general formula

h_max=h₀(M-m)/(M+m)+2h₀

where h₀ is initial height, M is larger mass and m smaller mass.

you sir, are a legend. REPPED!!!!!!!!!!!!!!!!!

 

[nml10]

I got 2.014

and the general formula

h_max=h₀(M-m)/(M+m)+2h₀

where h₀ is initial height, M is larger mass and m smaller mass.

THANK YOU SO MUCH!

 

[zxreth]

Question though, where did you get the formula from?

 

[Ferox]

It's just the same method the guy in the link above uses.

Basically the light one moves up h₀ metres, with a certain acceleration found from F=ma, till the heavy one hits the ground. Then the string becomes loose and the light one becomes a projectile. It's acceleration is now -g. Then just use v^2=V₀^2 + 2as a few times.

 

[zxreth]

yeah i tried that method from yahoo answers, but it didn't work. However the formula you got worked like a charm. Thanks though

 

[Ferox]

Well, he might have made a mistake, I just skimmed over it.

 

[Some Vunt]

OMG!

I'm gonna die!

This one question has taken me forever, I have a mental block!

HALP