What is the internal reaction force within the lower 80 cm length________________?
Show answer Hide answer
Answer: B. zero in first case
Explanation
Internal reaction forces in hanging structures depend entirely on the specific support and loading boundary conditions. For a freely hanging uniform bar supported only at the top, the internal force at the very bottom boundary is zero. Evaluating comparative cases with different boundary constraints confirms that lower segment internal forces change accordingly. Internal forces in continuous members are determined by cutting the body and applying static equilibrium equations. A free boundary condition cannot sustain any internal force or mechanical reaction at its extreme edge. Self-weight loading creates a linear distribution of axial force increasing from zero at the free end.
Option A is incorrect because differing boundary conditions alter the internal reaction force distributions. Option C contradicts the specific physical outcome where a free end condition eliminates lower edge force. Option D is wrong because the provided mechanics principles are entirely sufficient to determine the result.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Near the elastic limit region during a tensile test, what occurs to the______________?
Show answer Hide answer
Answer: A. tensile strain increases more quickly
Near the elastic limit region, atomic bonds begin slipping, causing tensile strain to increase at a much faster rate relative to stress. The material transitions from linear elastic behavior into non-linear plastic defor...
Q2. What is the peak frictional resistance encountered just as a body starts to slide over another surface called________________?
Show answer Hide answer
Answer: A. limiting friction
Limiting friction is the maximum peak frictional resistance encountered just before sliding starts. Static friction increases with applied load until it reaches this critical threshold value. Once motion begins, sliding...
Q3. What angle does an inclined surface make with the horizontal when an object on it is on the verge of sliding down__________________?
Show answer Hide answer
Answer: C. repose
The angle of repose is the maximum inclination angle of a plane with the horizontal at which an object on it remains at rest without sliding. At this specific threshold angle, the gravitational component pulling the obje...
Q4. What fundamental condition must be satisfied for a system of forces to be in static equilibrium_____________________?
Show answer Hide answer
Answer: C. both A. and B. above
A general three-dimensional force system requires forces to be coplanar and concurrent to satisfy static equilibrium conditions easily. Static equilibrium demands that both the vector sum of all forces and the sum of all...
Q5. How does a bar's deformation under its own weight compare to that caused by an equivalent external direct load_______________?
Show answer Hide answer
Answer: C. half
Deformation of a bar under its own weight equals half that of an equivalent end load. Distributed self-weight creates a varying tensile stress profile along the length of the bar. Integrating this distributed weight resu...
Q6. What is the allowable safe twisting moment for a composite shaft equivalent to_________________?
Show answer Hide answer
Answer: B. minimum calculated value
In composite shafts, the allowable safe twisting moment is governed by the weakest component, which corresponds to the minimum calculated value among the sections. Exceeding this lowest safe torque limit would cause the...