Concept explainers
A block of mass 3.00 kg is pushed up against a wall by a force
Figure P5.12
(a)
The possible value for the magnitude of force
Answer to Problem 12P
The possible value for the magnitude of force
Explanation of Solution
Assume that, the block is moving in upward direction to get maximum possible value of
Assume that, the net force along
Here,
From the free body diagram, write the expression for net force along
Here,
Write the expression for frictional force for maximum
Here,
Solve equation (II) for
Use equation (IV) in (III).
Assume that, the net force along
Here,
From the free body diagram, write the expression for net force along
Solve equation (VII) for
Assume that, the block is moving in downward motion to get minimum possible value of
Assume that, the net force along
From the free body diagram, write the expression for net force along
Solve equation (VII) for
Conclusion:
Substitute,
Substitute,
Substitute,
Therefore, The possible value for the magnitude of force
(b)
The result if
Answer to Problem 12P
When
Explanation of Solution
Maximum value of force
Conclusion:
Therefore,
(c)
The possible value for the magnitude of force
Answer to Problem 12P
The possible value for the magnitude of force
Explanation of Solution
Rewrite the equation (V) for angle
Rewrite the equation (VIII) for angle
Rewrite the equation (X) for angle
Conclusion:
Substitute,
Substitute,
It is not possible to be negative, so however large or small it is, it cannot produce upward motion
Substitute,
Therefore, The possible value for the magnitude of force
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Chapter 5 Solutions
Principles of Physics
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