Mechanic about wood block, friction and pulley

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SUMMARY

The discussion centers on a physics problem involving two objects, A and B, connected by a string over a pulley. Object A weighs 50 N and is on a horizontal surface with a coefficient of sliding friction (μ) of 0.3, while object B weighs 80 N and falls 2 meters. The solution requires calculating the velocity of B after falling, which is determined to be 2√2 m/s. The challenge lies in understanding the tension changes and friction effects during the motion.

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  • Understanding of Newton's laws of motion
  • Knowledge of friction coefficients and their application
  • Familiarity with pulley systems and tension forces
  • Basic algebra for solving equations of motion
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This discussion is beneficial for physics students, educators, and anyone interested in mechanics, particularly those studying dynamics involving friction and pulleys.

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Homework Statement


Two objects A and B weighing 50 N and 80 N respectively were connected by a light string over a fixed pulley. A was put on a reasonably long and horizontal table surface. The coefficient of sliding friction between A and the table surface is μ = 0.3 while the friction between the string and the pulley is neglected. Find the velocity of B after falling downwards for 2m. (Take g = 10 ms^-2)
Wa = 50 N
Wb = 80 N
μ = 0.3



The Attempt at a Solution


The question given that the object B falls when at start, thus when object B falls the tension change as the angle change, can't even start the 1st equation.
 

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any1 can help?? i still can't figure how to do this, this question is past year exam question but there's only answer provided. the ans is 2√2
 

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