One block on top of another (forces)

Discussion in 'Physics & Math' started by kingwinner, Oct 20, 2006.

  1. Pete It's not rocket surgery Registered Senior Member

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    Right... so what's the acceleration?
     
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  3. RubiksMaster Real eyes realize real lies Registered Senior Member

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    The acceleration would be the net force over the mass. So that would be applied force minus kinetic friction: 23.52N - 13.72N. The force is 9.8N. Divide that by the mass (7Kg) to get an acceleration of 1.4m/s^2.
     
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  5. Pete It's not rocket surgery Registered Senior Member

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    That's the mistake I made too.
    The 23.52N is the maximum force that the two blocks can apply on each other, right?
     
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  7. ashwin Registered Member

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  8. ashwin Registered Member

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    that is a wrong approach, since you have considered forces acting only on the 3 kg mass, its acceleration should 9.8/3 and not 9.8/7...because , in the solution you have considered A and B as two seperate systems and not as one single system of mass 7, A remains at rest wrt to B and B accelerates wrt the earth. There for A would have no net force acting on it wrt B.
     

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