# Mechanic about wood block, friction and pulley

1. Oct 16, 2012

### stranger123

1. The problem statement, all variables and given/known data
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

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, cant even start the 1st equation.

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2. Oct 17, 2012

### stranger123

any1 can help?? i still cant figure how to do this, this question is past year exam question but there's only answer provided. the ans is 2√2