University of Mumbai Engineering Mechanics viva questions PDF

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1. Basic of Engineering Mechanics Explain following terms

1. Engineering mechanics -ENGINEERING MECHANICS IS THE APPLICATION OF MECHANICS TO SOLVE PROBLEMS INVOLVING COMMON ENGINEERING ELEMENTS

Statics-THE BRANCH OF MECHANICS CONCERNED WITH BODIES AT REST AND FORCES IN EQUILIBRIUM.

2. 3. 4. 5. 6. 7.

Dynamics - DYNAMICS IS THE STUDY OF HOW MOVING OBJECTS BEHAVE Rigid body -A RIGID BODY IS AN IDEALIZATION OF A BODY THAT DOES NOT DEFORM OR CHANGE SHAPE Kinematics of particles Kinematics of rigid bodies Particle dynamics Rigid body dynamics - FORMALLY IT IS DEFINED AS A COLLECTION OF PARTICLES WITH THE PROPERTY THAT THE DISTANCE BETWEEN PARTICLES REMAINS UNCHANGED DURING THE COURSE OF MOTIONS OF THE BODY.

8. Mass - MASS IS A MEASURE OF THE AMOUNT OF MATERIAL IN AN OBJECT, BEING DIRECTLY RELATED TO THE NUMBER AND TYPE OF ATOMS PRESENT IN THE OBJECT. MASS DOES NOT CHANGE WITH A BODY'S POSITION, MOVEMENT OR ALTERATION OF ITS SHAPE, UNLESS MATERIAL IS ADDED OR REMOVED

9. Force - A FORCE IS A PUSH OR PULL UPON AN OBJECT RESULTING FROM THE OBJECT'S INTERACTION WITH ANOTHER OBJECT 10. Weight - THE WEIGHT OF AN OBJECT IS THE FORCE ACTING ON THE OBJECT DUE TO GRAVITY 11. Types of force system - THERE ARE TWO MAIN TYPES OF FORCE SYSTEMS NAMELY COPLANAR, NON-COPLANAR, CONCURRENT AND NONCONCURRENT

. 12. One Newton force - IT IS DEFINED AS THAT FORCE NECESSARY TO PROVIDE A MASS OF ONE KILOGRAM WITH AN ACCELERATION OF ONE METRE PER SECOND PER SECOND. ONE NEWTON IS EQUAL TO A FORCE OF 100,000 DYNES

13. Scalars - SCALARS ARE QUANTITIES THAT HAVE MAGNITUDE ONLY; THEY ARE INDEPENDENT OF DIRECTION 14. Vectors - A VECTOR IS A QUANTITY THAT HAS BOTH MAGNITUDE AND DIRECTION 15. Sine rule -THE LAW OF SINE OR THE SINE LAW STATES THAT THE RATIO OF THE SIDE LENGTH OF A TRIANGLE TO THE SINE OF THE OPPOSITE ANGLE, WHICH IS THE SAME FOR ALL THREE SIDES. IT IS ALSO KNOWN AS THE SINE RULE.

16. Cosine rule - THE LAW OF COSINES STATES THAT, IN A SCALENE TRIANGLE, THE SQUARE OF A SIDE IS EQUAL WITH THE SUM OF THE SQUARE OF EACH OTHER SIDE MINUS TWICE THEIR PRODUCT TIMES THE COSINE OF THEIR ANGLE

Explain following laws

1. Law of parallelogram of forces - THE LAW OF PARALLELOGRAM OF TWO FORCES STATES THAT IF TWO VECTORS ACTING ON A PARTICLE AT THE SAME TIME ARE REPRESENTED IN MAGNITUDE AND DIRECTION BY TWO ADJACENT SIDES OF A PARALLELOGRAM DRAWN FROM POINT THEIR RESULTANT IS REPRESENTED BY THE DIAGONAL OF THE PARALLELOGRAM DRAWN FROM THE SAME POINT

2. Newton’s first law of motion – NEWTON’S FIRST LAW, ALSO CALLED THE “LAW OF INERTIA”, STATES THAT AN OBJECT AT REST REMAINS AT REST, AND AN OBJECT THAT IS MOVING WILL CONTINUE TO MOVE STRAIGHT AND WITH CONSTANT VELOCITY, IF AND ONLY IF THERE IS NO NET FORCE ACTING ON THAT OBJECT.

3. Newton’s second law of motion –IT STATES THAT THE TIME RATE OF CHANGE OF THE MOMENTUM OF A BODY IS EQUAL IN BOTH MAGNITUDE AND DIRECTION TO THE FORCE IMPOSED ON IT.

4. Newton’s third law of motion - NEWTON'S THIRD LAW STATES THAT WHEN TWO BODIES INTERACT, THEY APPLY FORCES TO ONE ANOTHER THAT ARE EQUAL IN MAGNITUDE AND OPPOSITE IN DIRECTION. THE THIRD LAW IS ALSO KNOWN AS THE LAW OF ACTION AND REACTION.

5. Law of transmissibility of forces - THE PRINCIPLE OF TRANSMISSIBILITY STATES THAT THE POINT OF APPLICATION OF A FORCE CAN BE MOVED ANYWHERE ALONG ITS LINE OF ACTION WITHOUT CHANGING THE EXTERNAL REACTION FORCES ON A RIGID BODY.

2. Resultant of coplanar forces Explain following terms

1. Resultant - SINGLE (IMAGINARY) FORCE CALLED THE RESULTANT, WHICH ACTS AT A SINGLE POINT ON THE BODY, PRODUCING THE SAME NET FORCE AND THE SAME NET TORQUE. THE BODY CAN BE BROUGHT INTO EQUILIBRIUM BY APPLYING TO IT A REAL FORCE AT THE SAME POINT, EQUAL AND OPPOSITE TO THE RESULTANT.

2. VARIGNON’S THEOREM - MOMENT OF A FORCE ABOUT ANY POINT IS EQUAL TO THE SUM OF THE MOMENTS OF THE COMPONENTS OF THAT FORCE ABOUT THE SAME POINT.

3. Couple - A COUPLE IS A PAIR OF FORCES, EQUAL IN MAGNITUDE, OPPOSITELY DIRECTED, AND DISPLACED BY PERPENDICULAR DISTANCE OR MOMENT 4. Moment - THE TURNING EFFECT OF THE FORCE ON THE BODY ON WHICH IT IS ACTING IS MEASURED BY THE MOMENT OF A FORCE. THE MOMENT OF A FORCE DEPENDS ON THE MAGNITUDE OF THE FORCE AND THE DISTANCE FROM THE AXIS OF ROTATION.

5. Centroid - THE CENTROID OF A BODY IS THE POINT WHERE THERE IS EQUAL VOLUME ON ALL SIDES. THE CENTROID OF A SOLID BODY MADE FROM A SINGLE MATERIAL IS THE CENTER OF ITS MASS. IF THE MASS OF A BODY IS DISTRIBUTED EVENLY, THEN THE CENTROID AND CENTER OF MASS ARE THE SAME.

3. Equilibrium of coplanar forces Explain following terms

1. State and explain lami’s theorem

- WHEN THREE FORCES ACTING AT A POINT ARE IN EQUILIBRIUM, THEN EACH FORCE IS PROPORTIONAL TO

THE SINE OF THE ANGLE BETWEEN THE OTHER TWO FORCES

2. Free body diagram – 3. Reactive force - A REACTION FORCE IS A FORCE THAT ACTS IN THE OPPOSITE DIRECTION TO AN ACTION FORCE 4. conditions of equilibrium for two dimensional force system 5. Types of supports used in beams - ROLLER, PINNED AND FIXED 6. Types of loads on beam - POINT LOADS, DISTRIBUTED LOADS, OR VARYING LOADS 7. Assumptions made in the analysis of plane trusses 8. Perfect and imperfect trusses 9. Application of trusses 10. Statically determinate and indeterminate trusses 11. Method of joints - THE METHOD OF JOINTS IS A PROCEDURE FOR FINDING THE INTERNAL AXIAL FORCES IN THE MEMBERS OF A TRUSS 12. Method of sections 13. Difference between above two 14. Application of above two

15. How to find zero force members by observation

4. Friction Explain following terms

1. 2. 3. 4.

State laws of static friction. Define friction - FRICTION IS A FORCE BETWEEN TWO SURFACES THAT ARE SLIDING, OR TRYING TO SLIDE, ACROSS EACH OTHER Limiting friction force - THE MAXIMUM FRICTION THAT CAN BE GENERATED BETWEEN TWO STATIC SURFACES IN CONTACT WITH EACH OTHER Coefficient of static friction - THE COEFFICIENT OF STATIC FRICTION IS THE RATIO OF THE MAXIMUM STATIC FRICTION FORCE (F) BETWEEN THE SURFACES IN CONTACT BEFORE MOVEMENT COMMENCES TO THE NORMAL (N) FORCE.

5. Coefficient of kinetic friction - THE KINETIC FRICTION COEFFICIENT ΜK IS THE RATIO OF THE FRICTION FORCE TO THE NORMAL FORCE EXPERIENCED BY A BODY MOVING ON A DRY, NON-SMOOTH SURFACE

6. Angle of friction- IT IS THE ANGLE MADE BY THE RESULTANT OF THE LIMITING FRICTIONAL FORCE FMAX AND THE NORMAL REACTION N WITH THE NORMAL REACTIONS

7. Angle of repose - THE ANGLE THAT THE PLANE OF CONTACT BETWEEN TWO BODIES MAKES WITH THE HORIZONTAL WHEN THE UPPER BODY IS JUST ON THE POINT OF SLIDING

8. Cone of friction 9. Wedges and application of wedge friction 10. Prove that angle of friction is equal to angle of repose 11. Explain ladder friction

5.

Space forces

Explain the Conditions of equilibrium of three dimensional force systems

6. Kinematics of particles Explain following terms

1. Particle dynamics 2. Define following terms 3. Distance 4. Displacement 5. Position 6. Velocity 7. Speed 8. Acceleration 9. Rectilinear motion 10. Constant velocity motion 11. Constant acceleration motion 12. Variable acceleration motion

13. How to draw x-t, v-t and a-t curves for above motions 14. Curvilinear motion 15. Normal acceleration 16. Tangential acceleration 17. Radius of curvature 18. Comment on velocity in a curvilinear motion 19. Comment on acceleration in curvilinear motion 20. Define projectile motion 21. Relative motion

7. Kinematics of rigid bodies Explain following terms

1. 2. 3. 4.

Rigid body dynamics Explain the term pure rotational motion, pure translational motion and general plane motion Instantaneous centre of rotation What are the steps to find the ICR of a general Plane body

8. Kinetics of particles Explain following terms

1. What is De’ Alembert’s Principle 2. What is constant string length method 3. Define work energy principle 4. Work done by weight force 5. Work done by spring force 6. Work done by externally applied force 7. Work done by friction force 8. Define plastic body 9. Law of conservation of momentum 10. Elastic body 11. Plastic Body 12. Plastic impact 13. Elastic impact 14. Line of impact 15. Types of impact 16. Coefficient of restitution 17. Phenomenon of impact

9. Questions based on Practical 1. 2. 3. 4. 5.

Aim of a particular experiments Results obtained Procedure to perform experiment Different components of the apparatus used for particular experiment and their functions Explanation on the graphs drawn if any...