Physics Help Forum Acceleration of a wedge

 Dec 2nd 2017, 09:42 AM #1 Junior Member   Join Date: Dec 2017 Posts: 1 Acceleration of a wedge Problem A wedge with mass M rests on a frictionless horizontal tabletop. A block with mass m is placed on the wedge. There is no friction between the block and the wedge. The system is released from rest. Calculate the acceleration of the wedge. Included diagrams What I Tried I know that the answer ends up being: $a_1=\frac{m_2gsinθcosθ}{m_1+m_2sin^2θ}\$ but the system of equations I come up with does not give me that answer $\displaystyle (1) -Nsinθ=m_1a_1$ $\displaystyle (2) Ncosθ-m_2g=m_2a_2sinθ$ $\displaystyle (3) Nsinθ=m_2(a_2cosθ+a_1)$ The answer for $\displaystyle a_1$ that I derive from that comes fairly close to the intended answer, but I don't see where I went wrong with my identification of forces. Thanks in advance for any help. Answer I get from those equations $a_1=\frac{m_2gsinθcosθ}{2m_1sin^2θ+m_2sin^2θ-m_1}\$