Question

How can we find acc. in pulley question?​

Answer 1

Answer:

Masses M1M1 and M2M2 are connected to a system of strings and pulleys as shown. The strings are massless and inextensible, and the pulleys are massless and frictionless. Find the acceleration of M1M1.

Clue: If M2=M1M2=M1, acceleration (AA) will be A=g5A=g5

My attempt:

Let TT be the tension of the rope connected to M2M2. So the tension of the rope connected to M1M1 will be 2T2T. The acceleration of both the masses is AA.

Now, M2g−T=M2A(1)(1)M2g−T=M2A

2T−M1g=M1A(2)(2)2T−M1g=M1A

From 11 and 22,

A=g(2M2−M1)(2M2+M1)

A=g(2M2−M1)(2M2+M1)

Now if M2=M1M2=M1, I get, A=g3A=g3.

But the answer is A=g5A=g5

Where am I wrong? Will the accelerations of M1M1 and M2M2 not be the same? or, are there anything about the tensions ?

Answer 2

Explanation:

clue : if M2 = M1 M2 = M1 acceleration ( AA) will be A = g5 = g5