# Homework Help: Need help - problem newton laws + my try

1. Sep 4, 2008

### sedaw

TNX !

http://img377.imageshack.us/img377/8561/00000qj1.jpg [Broken]

Last edited by a moderator: May 3, 2017
2. Sep 4, 2008

### dirk_mec1

So t =T1. Why is the acceleration 2a in the second equation?

3. Sep 4, 2008

### sedaw

yes T1=t

and m1 distance double m2 distance that`s why the acceleration proportion is 2:1

is that right ?

4. Sep 4, 2008

### dirk_mec1

No that's not correct where did you get that idea?

5. Sep 4, 2008

### sedaw

can you be more specific , what is not correct and how to solve the problem ?

TNX .

6. Sep 4, 2008

### Staff: Mentor

I don't see anything wrong with your equations. Solve them to find a.

7. Sep 4, 2008

### sedaw

t-m_1gsin30=m_1*2a \ *2
+
m_2g-2t=m_2*a

m_1=m_2 = 5kg

2t - 2t - 2*5*0.5g + 5g= 20a+5a

0=25a ====> ??????????????

the answer in the book is a=2.8

how is that ????

plzz help .

8. Sep 4, 2008

### Staff: Mentor

Oops. It looks like the masses are in equilibrium if they are equal. Are you sure you have the masses correct? (Also, what book are you using?)

9. Sep 5, 2008

### sedaw

yea i am sure .

the book is classical mechanics by yoram eshel .