 #1
Monsterboy
 301
 95
 Homework Statement:

Consider the situation shown in figure. Both the pulleys and the string are light and all the surfaces are frictionless. Find the acceleration of the mass M and the tension in the string in the
figure given below.
 Relevant Equations:
 Freebody diagrams and the forces acting on them.
I solved this problem by assuming that the acceleration ##a## is the same on the both the masses M and 2M but then answers were wrong, but if the acceleration of the mass 2M is considered as ##a/2## then I get the right answers, but I don't how exactly acceleration is getting halved for mass 2M.
How do I show that the acceleration of the mass 2M is ##a/2## if the acceleration of M is ##a## ?