Oh sorry !
actually that is the main problem for me... I thought that M is affected by the weight and the normal force but I can't figure a relation between M and the tension.
sorry for not understanding your reply before!
the question didn't mention any external force, it just said that m1 can only move in the vertical direction plus that there is no friction in the whole system
Can anyone please explain to me how can I calculate the "Tension" and "acceleration" of M in this question interms of M,m1,m2 and g?
I can't understand how M has an acceleration or why M is involved in the calculation of the tension
my solution was that acc of M is zero
and Tension = m1g x...