What is the mechanics? What are the categories of mechanics?

A.Questions

1. 
   What is the mechanics? What are the categories of mechanics?
   

Answer: -Mechanics is the science which describes and predicts the conditions of rest or motion of bodies under the action of forces.
Categories of Mechanics: - Rigid bodies
- Statics
- Dynamics
- Deformable bodies
- Fluids.
2. Define the fundamental concepts used in mechanics
Answer: The basic concepts used in mechanics are space, time, mass, and force:

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  Space - associated with the notion of the position of a point given in terms of three coordinates measured from a reference point or origin.
  
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  Time - definition of an event requires specification of the time and position at which it occurred.
  
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  Mass - used to characterize and compare bodies, e.g., response to earth’s gravitational attraction and resistance to changes in translational motion.
  
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  Force - represents the action of one body on another. A force is characterized by its point of application, magnitude, and direction, i.e., a force is a vector quantity.
  

3. What fundamental principles on which the study of mechanics is based on?
Answer: The study of elementary mechanics rests on six fundamental principles based on experimental evidence:

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  Parallelogram Law
  
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  Principle of Transmissibility
  
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  Newton’s First Law
  
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  Newton’s Third Law
  
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  Newton’s Second Law
  
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  Newton’s Law of Gravitation
  

4. What are the kinetic units? Explain the system of units
Answer:
- The four fundamental concepts introduced in the preceding section are associated the so-called kinetic units: the units of length, time, mass, and force.
- Kinetic units selected in this way are said to form a system of units.

5. What are the significant Figures? How to round off numbers?
Answer: -The number of significant figures is usually inferred by the number of figures given except for leading zeros.

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  Rounding off a number is necessary so that the accuracy of the result will be the same as that of the problem data.
  
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  As a general rule, any numerical figure ending in a number greater than five is rounded up and a number less than five is not rounded up:
  

Ex: If 3.5587 is to be rounded off to three significant figures → 3.56; 0.5896 → 0.590 and 9.3866 becomes 9.39.

Part B: