- #1
ShizukaSm
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Homework Statement
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Find acceleration of block 1, knowing that the mass of block 1 is 2kg and of block 2 is 4kg. You may ignore friction and pulley mass.
Homework Equations
Fr = ma
The Attempt at a Solution
I Drew free body diagrams to block 1, 2 and the pulley, then made the equations:
[itex]
\\
\sum F_{r2} = m_2a_2\\
P_2 - T_2 = m_2a_2\\
\\
\sum F_{rpulley} = m_{pulley}*a\\
2T_2 = T_1\\
\\
\sum F_{1}=m_1a_1\\
T_1=m_1a_1\rightarrow T_2 = \frac{m_1a_1}{2}
\\\\a_1=2a_2 \rightarrow T_2=\frac{m_1(2a_2)}{2} = m_1a_2
\\(Substituting\ in \ first\ equation)\\
P_2-(m_1a_2)= m_2a_2\\
a_2(m_2+m_1) = m_2*g\\\\
a_2=\frac{m_2g}{m_2+m_1} = 6.53\frac{m}{s^2}\rightarrow a_1 = 13.06\frac{m}{s^2}
[/itex]
The answer, however, is supposed to be 4.4 m/s²
Thanks in advance!