Lowering an object without breaking the the rope

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To lower a 1000 N object using a cord with a breaking strength of only 800 N, the acceleration must be reduced so that the net force does not exceed the cord's limit. The weight of the object is calculated as 1000 N, which corresponds to a mass of approximately 102.04 kg. The attempt to find the acceleration resulted in a value of 7.84 m/s², which is incorrect as it does not account for the tension in the cord. A free body diagram should be drawn to visualize the forces acting on the object, which include weight and tension. The correct approach involves ensuring the sum of forces remains within the safe limits of the cord's breaking strength.
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Homework Statement


How could a 1000 N object be lowered from a roof using a cord whose breaking strength is only 800 N?

Homework Equations


∑F=ma

The Attempt at a Solution


By slowing down the acceleration to a point where the force down would be less than 800.
weight=m(g)
1000N=m(9.8)
102.04kg=m
∑F=ma
799.99=102.04kg(a)
7.84m/s^2=a
Would this be the right answer?
 
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This is not the correct answer. Be sure to draw a free body diagram of the object. How many forces act on the object as it is being lowered?
 
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TSny said:
This is not the correct answer. Be sure to draw a free body diagram of the object. How many forces act on the object as it is being lowered?
The two forces are weight and force tension. Where did I go wrong exactly?
 

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Diagram looks good. When you set up ∑F = ma, the left side represents the vector sum of the two forces.
 
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