- #1
Lil_Aziz1
- 21
- 1
Hey everyone. I'm kind of stumped on this example from my textbook. It uses angular momentum to solve an Atwood's machine problem. Here is how the problem and the solution goes:
My question is, why does the book use force of gravity as the force acting on the pulley instead of the tension? the book did this problem previously using only Newton's second law, i.e.,
I did the angular momentum problem but replaced [tex]m_{1}g[/tex] and [tex]m_{2}g[/tex] with [tex]T_1=m_1(g-a)[/tex] and [tex]T_2=m_2(g+a)[/tex], respectively. Consequently, for linear acceleration I got [tex]a=\frac{m_1-m_2}{m_1+m_2+0.5M}\frac{g}{2}[/tex] (notice the g/2)
Can anyone explain to me why it's doing that?
Thanks in advance.
My question is, why does the book use force of gravity as the force acting on the pulley instead of the tension? the book did this problem previously using only Newton's second law, i.e.,
I did the angular momentum problem but replaced [tex]m_{1}g[/tex] and [tex]m_{2}g[/tex] with [tex]T_1=m_1(g-a)[/tex] and [tex]T_2=m_2(g+a)[/tex], respectively. Consequently, for linear acceleration I got [tex]a=\frac{m_1-m_2}{m_1+m_2+0.5M}\frac{g}{2}[/tex] (notice the g/2)
Can anyone explain to me why it's doing that?
Thanks in advance.