How to calculate acceleration in this Atwood's Machine?

AI Thread Summary
The discussion focuses on calculating the acceleration in an Atwood's machine, where the user initially miscalculated the net forces on both blocks. The net force on block B was determined to be (300 - 3T) and on block A as 2T, leading to an incorrect acceleration of 1.71 instead of the correct 1.56. Participants emphasized the importance of recognizing that the two blocks have different accelerations due to the string constraint. The final resolution highlighted the relationship between the accelerations of blocks A and B, clarifying the calculations needed for accurate results. Understanding the distinct accelerations was crucial for solving the problem correctly.
ArnavVarshney
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Homework Statement
Question: https://i.stack.imgur.com/xYp18.jpg

It asks us to find the acceleration of block B.
Relevant Equations
String constraint?
I concluded the net force on block B would be (300-3T) where T is the tension in the string and similarly, on block A it would be 2T. However, the answer I get (1.71) is incorrect. The correct answer is 1.56.
Could someone guide me to the solution of the question.
Sincere Thanks!
 
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Show us your calculations to be able to tell you what you did wrong.
 
ArnavVarshney said:
Problem Statement: Question: https://i.stack.imgur.com/xYp18.jpg

It asks us to find the acceleration of block B.
Relevant Equations: String constraint?

I concluded the net force on block B would be (300-3T) where T is the tension in the string and similarly, on block A it would be 2T. However, the answer I get (1.71) is incorrect. The correct answer is 1.56.
Could someone guide me to the solution of the question.
Sincere Thanks!
How does the acceleration of A compare to the acceleration of B?
 
Chestermiller said:
How does the acceleration of A compare to the acceleration of B?
By string constraint, work done by tension would be zero. So, -3T(aB) + 2T(aA) = 0.
2aA = 3aB?
 
Chestermiller said:
How does the acceleration of A compare to the acceleration of B?
Done! Thanks a lot! Was missing out on the fact that the two would have different accelerations!
 
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