R13 B.Tech I year syllabusJAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

I Year B.Tech.LT/P/DC

3-/-/-6

ENGINEERING MECHANICS

UNIT IIntroduction to Engineering Mechanics Basic Concepts. Resultants of Force System: Parallelogram law Forces and components- Resultant of coplanar Concurrent Forces Components of forces in Space Moment of Force - principle of moments Coplanar Applications Couples - Resultant of any Force System.Equilibrium of Force Systems : Free Body Diagrams, Equations of Equilibrium - Equilibrium of planar Systems - Equilibrium of Spatial Systems.UNIT IIFRICTION: Introduction Theory of Friction Angle of friction - Laws of Friction Static and Dynamic Frictions Motion of Bodies: Wedge, Screw, Screw-jack, and Differential Screw-jack.Transmission of Power: Flat Belt Drives - Types of Flat Belt Drives Length of Belt, tensions, Tight side, Slack Side, Initial and Centrifugal Power Transmitted and Condition for Max. Power.UNIT IIICENTROIDS AND CENTERS OF GRAVITY: Introduction Centroids and Centre of gravity of simple figures (from basic principles ) Centroids of Composite Figures - Theorem of Pappus Center of gravity of bodies and centroids of volumes. Moments of Inertia : Definition Polar Moment of Inertia Radius of gyration - Transfer formula for moment of inertia - Moments of Inertia for Composite areas - Products of Inertia, Transfer Formula for Product of Inertia.Mass Moment of Inertia : Moment of Inertia of Masses- Transfer Formula for Mass Moments of Inertia - mass moment of inertia of composite bodies.UNIT IVKINEMATICS OF A PARTICLE: Motion of a particle Rectilinear motion motion curves Rectangular components of curvilinear motion Kinematics of Rigid Body - Types of rigid body motion -Angular motion - Fixed Axis Rotation Kinetics of particles: Translation -Analysis as a Particle and Analysis as a Rigid Body in Translation Equations of plane motion - Angular motion - Fixed Axis Rotation Rolling Bodies.UNIT VWORK ENERGY METHOD: Work energy Equations for Translation - Work-Energy Applications to Particle Motion Work energy applied to Connected Systems - Work energy applied to Fixed Axis Rotation and Plane Motion. Impulse and momentum.Mechanical Vibrations : Definitions and Concepts Simple Harmonic Motion Free vibrations, simple and Compound Pendulums Torsion Pendulum Free vibrations without damping: General cases.TEXT BOOKS:1. Engineering Mechanics - Statics and Dynamics by Ferdinand.L. Singer / Harper International Edition.

2. Engineering Mechanics/ S. Timoshenko and D.H. Young, Mc Graw Hill Book Compan.

REFERENCES:1. Engineering Mechanics / Irving Shames / Prentice Hall

2. A text of Engineering Mechanics /YVD Rao/ K. Govinda Rajulu/ M. Manzoor Hussain, Academic Publishing Company

3. Engg. Mechanics / M.V. Seshagiri Rao & D Rama Durgaiah/ Universities Press

4. Engineering Mechanics, Umesh Regl / Tayal.

5. Engg. Mechanics / KL Kumar / Tata McGraw Hill.

6. Engg. Mechanics / S.S. Bhavikati & K.G. Rajasekharappa

6www.jntuworld.comENGINEERING MECHANICSQUESTION BANKUNIT-I

PART-A1. Distinguish the following system of forces with a suitable sketch. a) Coplanar b) Collinear 2. Define Kinetics and Kinematics 3. State Lamis theorem with a sketch. 4. State parallelogram law and triangle law of forces. 5. What are fundamental and derived units? Give examples 6 . 6. Distiguish between units and dimensions. Give examples.7. 7. Define principle of transmissibility. 8. 8. A force vector F= 700i + 1500j is applied to a bolt. Determine the magnitude of the force and angle it forms with the horizontal. 9. A force of magnitude 50 KN is acting along the line joining A(2,0,6) and B(3,-2,0)m. Write the vector form of the force. 10. Two forces of magnitude 50 KN and 80 KN are acting on a particle, such that the angle between the two is 135. If both the force are acting away from the particle, calculate the resultant and find its direction. 11. A 100N force acts at the origin in a direction defined by the angles x = 75 and y = 45.Determine z and the component of the force in the Z-direction.12. Write the equations of equilibrium of a coplanar system of forces. 13. Differentiate between Resultant and Equilibrant 14. Find the resultant of an 800N force acting towards eastern direction and a 500N force acting towards north eastern direction. 15. Find the magnitude of the two forces such that if they act at right angles, their resultant is10N. But if they act at 60 their resultant is 13 N. PART-B1.The forces shown in the figure below are in equilibrium. Determine the forces F1 and F2

2.Determine the tension in cables AB & AC to hold 40 Kg load shown in fig.

3. A force P is applied at O to the string AOB as shown in fig. If the tension in each part of string is 50 N, find the direction an magnitude of force P for equilibrium conditions.

4. Two identical rollers each of weight 50N are supported by an inclined plane and a vertical wall as shown in fig. Find the reactions at the points of supports A, B, and C.

5. A tower guy wire shown below is anchored by means of a bolt at A as shown. The tension in the wire is 2500kN.

6. Determine

(a) The components Fx, Fy & Fz of the force acting on the bolt

(b) The angles _x, _y, _z defining the direction of the force.

7. Members OA, OB and OC form a three member space truss. A weight of 10 KN is suspended at the joint O as shown in fig. Determine the magnitude and nature of forces in each of the three members of the truss

8. A crane shown in figure is required to lift a load of W=10 KN. Find the forces in the members AB and CB

9. A precast concrete post weighing 50 Kg and of length 6m shown in fig. is raised for placing it in position by pulling the rope attached to it. Determine the tension in the rope and the reaction at A.

Objective

I. Choose the correct alternative:

1.A force is specified by[]

(a) Magnitude(b) direction of its action (c) Point of application of force(d) all of the above

2.Newtons III law of motion is stated as[]

(a) Every particle remains at rest or continues to move in a straight line with uniform velocity if there is no unbalanced force acting on it

(b) Rate of change of momentum of a particle is proportional to the unbalanced force acting on it

(c) To every action, there is an equal and opposite reaction

(d) None of the above

3. Law of parallelogram of forces states that if two forces acting on a particle are represented in

magnitude and direction by two sides of the parallelogram then their resultant is

given by[]

(a) Sum of two forces(b) Product of two forces

(c) Diagonal of the parallelogram(d) None of the above

4.Quantities, which have both magnitude and direction, are known as[]

(a) Vectors (b) Scalars(c) Numbers(d) none of the above

5.The forces, which do not meet at a point, are known as[]

(a) Non coplanar forces(b) non con current forces (c) Coplanar forces(d) concurrent force

6.Roller support has reaction[]

(a) Only in horizontal direction(b) Only in vertical direction

(c) In both horizontal and vertical direction(d) none of the above

7.A sketch showing physical and geometrical conditions of system is[]

(a) Space diagram (b) Free body diagram(c) Neat diagram (d) None of the above

8.If a body is in equilibrium under the action of three forces, the three forces must be[]

(a) Concurrent(b) Parallel(c) Either concurrent or parallel(d) none of the above

9. According to Lamis theorem, if a body is in equilibrium under the action of three forces, each force

is proportional to ----------- of the angle between the other two[]

(a) Sine(b) Cosine(c)Tangent (d) None of the above

10. When a member is in equilibrium under the action of two forces it is called[]

(a) One force member(b) Two force member

(c) Three force member(d) Multi force member

IIFill in the Blanks:11. The forces whose lines of action lie in the same plane and are meeting at one point are _________

12. A force represented in three dimensions is_________

13. Conditions of equilibrium in statics are __________

14. When the resultant force R and the resultant couple vector M have same line of action, then the system is known as ________.

15. Example of both positive and negative wrench is ______.

16. If the resultant of two forces P and Q acting at an angle with P then Tan =____.

17. In a couple, the lines of action of the forces are

18.Lamis theorem can be applied forforces.

19. If a beam is projecting beyond the support, it is called

20.A couple consists of.

UNIT II

PART-A1. State Varignons theorem 2. What is a couple? What is a moment of a couple? 3. A force vector F has the components Fx = 150N, Fy= -200N and Fx = 300N. Determine the magnitude F and the angle made by the force with coordinate axes. 4. Sketch the different types of supports. 5. Write down the conditions of equilibrium of a particle in space 6. A force vector of magnitude 100N is represented by a line of coordinates A (1, 2, 3) and B (5, 8, 12). Determine components of the force along X, Y and Z axes. 7. Explain will you reduce a force into an equivalent force-couple system with an example. 8. Draw Compute the moment of the 100 N force about point A and B

PART-B1. Four forces act on a 700mm X 375mm plate as shown in fig. a) Find the resultant of these forces b) Locate the two points where the line of action of the resultant intersects the edge of the plate.

2. Four coplanar non concurrent non parallel forces act on a square plate of side 2m as shown in fig. Locate the resultant force.

3. In figure below, two forces act on a circular disc as shown. If the resultant moment of all these forces about point D on the disc is zero, determine: a) Magnitude of force P (b) Magnitude of the resultant of two forces (c) The point on the Y-axis through which the line of action of the resultant passes through.

4. Four forces act on a square of side 1 m as shown in fig. Reduce the force system into an equivalent force couple system at A.

5.Reduce the system of forces shown in fig.5 to a force couple system at A.

6. Blocks A and B of weight 200N and 100N respectively, rest on a 30 inclined plane and are attached to the post which is held perpendicular to the plane by force P, parallel to the plane, as shown in fig. Assume that all surfaces are smooth and that the cords are parallel to the plane. Determine the value of P. Also find the Normal reaction of Blocks A and B.

7. A Uniform meter rod AB, assumed rigid of mass 0.5 kg is suspended from its ends in an inclined position and a mass of 1 kg is suspended from a point D, as shown in fig. Determine the tension in each string. Where the suspended mass should be placed in order to get equal tension in the strings.

8. A rod AB of weight 200 N is supported by a cable BD and the corner of wall and floor surface as shown in fig. Find the reaction at A and tension in the cord.

9.Find reactions at points A & B

40KN30KN

20KN

10KN

600700

AB

1.5m1m2m0.5

Objective

I. Choose the correct alternative:

1.The C.G.of solid right circular cone lies on the axis at a height[]

A)half of total height above baseB)one third of total height above base

C)one fourth of total height above baseD)none of the above.

2.The point through which the whole weight of body acts is[]

A)center of gravityB)area moment of inertia

C)polar moment of inertiaD)none of the above

3. Moment of inertia of triangular section of base b and height h about an axis passing

through its vertex and parallel to the base istimes as that passing through its

C.G. and parallel to the base.[]

A) 2B) 4C) 8D) 9

4.Unit of mass moment of inertia is[]

A) Kg.m2B) m4C)Kg.mD) none of the above

5.A circular hole of radius (r ) is cut out from a circular disc of a radius (2 r ) in such a way that the

diagonal of the hole is the radius of the disc .The C.G. of the section lies at[]

A) Center of discB) Center of holeC) Some where in the disc D) some where in the hole

6.Which of the following represents perpendicular axis theorem.(Generally)[]

A) Ix=Iy+Iz B)Iz=Ix+Iy C)Iy=Iz+IxD) Iz=Ix-Iy

7.If first moment wrt any axis is zero,then the axis must be[]

A) centroidal axisB) co-ordinate axisC)both a and b D) none of the above

8. Volumes of revolution is generated by revolving ______about fixed non intersecting axis

[]

A) lineB) areaC) volumeD) none of the above

9.The truss in which members can not rotate freely at the joints is[]

A) Plane TrussB) space truss C)Rigidly connected trussD) pin connected truss

10.Space truss is __ dimensional truss.[]

A) 1B) 2C) 3D) none of the above

IIFill in the blanks11. The C.G. of a uniform rod lies at its_______

12. The C.G. of a circle lies at its_______

13. When one or more component is a multi force member and all members are immovable, the structure is known as _______

14. Moment of inertia of circular section of diameter d is ________

15. Moment of inertia of triangular section of base b and height h about an axis passing through its

C.G. and parallel to the base is

16. Mass moment of inertia of a sphere about centroidal axis XX is

17. Moment of inertia of elliptical section of major axis a and minor axis b is

18. The C.G. of hollow pyramid lies on the central axis above base at a distance of_____.

19. Radius of gyration of solid sphere of radius R is

20.Centroidal distance between centroid and centroidal axes is.

UNIT III

PART-A1. State parallel axis theorem 2. State perpendicular axis theorem 3. Find the polar moment of inertia of a hollow circular section of external diameter D and internal diameter d 4. Define principal axes and principal moment of inertia 5. Locate the centroid and calculate the moment of inertia about centroidal axes of a semicircular lamina of radius 2m. 6. A semicircular area having a radius of 100 mm is located in the XY-plane such that its diameter coincides with Y-axis. Determine the X-coordinate of the center. 7. Distinguish between centroid and center of gravity. 8. Define polar moment of inertia. 9. Differentiate between Mass moment of inertia and Area moment of inertia 10. Write down the expression for finding mass moment of inertia of a cylinder of radius R and height h about its base. PART-B1.Determine the co-ordinates of Centroids of the shaded area shown in figure.

2. A Cylinder of height of 10 cm and radius of base 4 cm is placed under sphere of radius 4 cm such that they have a common vertical axis. If both of them are made of the same material, locate the centre of gravity of the combined unit. 3. Find the moment of inertia of the section shown in the figure about its horizontal centroidal axis.

4. Calculate the mass moment of inertial of the plate shown in figure with respect to the axis AB. Thickness of the plate is 5 mm and density of the material is 6500 Kg/m3.

5.Derive expression form mass moment of inertia of prism along three axes.Objective

I. Choose the correct alternative:

1.Mass moment of inertia of a body is always[]

A. Positive B. Negative C. zeroD. none of the above

2. The series of straight members connected together such that no member is Continuous through a

joint is[]

A. JointB. trussC. FrameD. machine

3.The C.G. of a thin hollow right circular cone lies on the axis at a height of[]

A. half of total heightB. one third of total height

C. one fourth of total heightD. none of the above

4.Mass moment of inertia of solid sphere of mass M and radius R is[]

A. 2MR2/5B. 2MR2/7C. 2MR2/9D. 2MR2/11

5.Perpendicular axis theorem is used in obtaining the moment of inertia of[]

A. triangular sectionB. square sectionsC. Circular SectionsD. None of the above

6.The center of gravity of a triangle lies at the point of concurrence of[]

A. the right bisectors of the angle of the triangleB. the medians of the triangle

C.the altitudes from the vertices on the opposite sideD. none of the above

7.A circular hole of radius (r ) is cut out from a circular disc of a radius (2 r ) in such away that the

diagonal of the hole is the radius of the disc .The C.G. of the section lies at[]

A. Center of discB. Center of hole

C. Some where in the discD. some where in the hole

8.The center of gravity of solid hemisphere lies on the central radius at a distance[]

A. 3R/4 from the plane baseB. 3R/8 from the plane base

C. 8R/3 from the plane baseD. None of the above

9. A thin rod of length L and mass M will have moment of inertia about an axis passing through one of

its edge and perpendicular to the rod,[]

A. ML2/12 B. ML2/6C. ML3/3D. ML2/3

10. Moment of inertia of a triangular section about an axis passing through its base(b=width at base and

height =h) is[]A. bh3/12B. bh3/32C. bh2/36D. None of the aboveIIFill in the blanks:11. Rouths rule is used for obtaining________

12. The truss whose members are connected by smooth pins is ______.

13. Product of inertia of quarter circle of radius r about its base line is _____

14. When one or more component is a multi force member and all members are immovable, the structure is known as _______

15. The point through which the whole weight of body acts is______

16. Volumes of revolution is generated by revolving ______about fixed non intersecting axis

17. For equilibrium of structure, the resultant of all forces and the resultant of all moments acting on the structure should be

18. The center of gravity of a semi circular arc is at the central radius at a distance of ____.

19. The center of gravity of a thin hollow right circular cone lies on the axis at a height ____.

20.The center of gravity of a thin hollow hemisphere is at a distance of.

UNIT IV

PART-A1. Define DAlemberts principle 2. Write down the equations of motion of a particle under gravitation 3. A car accelerates uniformly from a sped of 30 Km/Hr to a speed of 75 Km/Hr in 5 secs. Determine the acceleration of the car and the distance traveled by the car during 5 secs. 4. Explain dynamic equilibrium 5. State the law of conservation of momentum 6. A car starts from rest with a constant acceleration of 4m/sec2. Determine the distance traveled in the 7th second. 7. A point P moves along a straight line according to the equation x= 4t3+2t+5, where x is in meters and t is in secs. Determine the velocity and acceleration at t=3 secs. 8. A stone is projected in space at an angle of 45 to horizontal at an initial velocity of 10 m/sec. Find the range of the projectile. 9. What is work energy principle? 10. Write the impulse momentum equation.

PART-B1. A train is traveling from A to D along the track shown in fig. Its initial velocity at A is zero. The train takes 5 min to cover the distance AB, 2250 m length and 2.5 minutes to cover, the distance BC, 3000 m in length, on reaching the station C, the brakes are applied and the train stops 2250 m beyond, at D (i) Find the retardation on CD, (ii) the time it takes the train to get from A to D, and (iii) its average speed for the whole distance. 2. The position of the particle is given by the relation S=1.5t3-9t2-22.5t+60, where S is expressed in meters and t in seconds. Determine (i) the time at which the velocity will be zero (ii) the position and distance traveled by the particle at that time (iii) the acceleration of the particle at that time and (iv) the distance traveled by the particle from t = 5s to t = 7s. 3. A particle is projected with a initial velocity of 12m/s at an angle M with the horizontal. After sometime, the position of the particle is observed by its x and y distances of 6m and 4m respectively from the point of projection. Find the angle of projection. 4. Two Blocks A and B of weight 100 N and 200 N respectively are initially at rest on a 30 inclined plane as shown in figure. The distance between the blocks is 6 m. The co efficient of friction between the block A and the plane is 0.25 and that between the block B and the plane is 0.15. If they are released at the same time, in what time the upper block (B) reaches the Block (A).

5. Two blocks of weight 150 N and 50 N are connected by a string and passing over a frictionless pulley as shown in figure. Determine the acceleration of blocks A and B and the tension in the string.

6. Two weights 80 N and 20 N are connected by a thread and move along a rough horizontal plane under the action of a force 40 N, applied to the first weight of 80 N as shown in figure. The coefficient of friction between the sliding surfaces of the wrights and the plane is 0.3. Determine the acceleration of the weights and the tension in the thread using work-energy equation.

7. Two blocks of weight 150N and 50N are connected by a string, passing over a frictionless pulley as shown in fig. Determine the velocity of 150N block after 4 seconds. Also calculate the tension in the string.

8. Two bodies, one of mass 30kg, moves with a velocity of 9m/s centrally. Find the velocity of each body after impact, if the coefficient of restitution is 0.8. 9. A Force F = 30N acts parallel to the inclined plane as it accelerates a block of mass m = 2kg up to the 300 incline with a coefficient of kinetic friction k = 0.3 as shown in figure. A spring whose force constant K is 40 Nm-1 is attached to the block which starts from rest at a position x = 0, where the spring is unstressed. Find the speed of the block after travelling 0.2 m up the incline? Use Work-Energy method.

F300Objective

1.When a body is thrown, the time of flight (t) is equal to[]

A.u sinB.2u sinC.2gD.g

2ggu sin2 u sin

2.The velocity of projectile at a height h is equal to __________[]

A.u2 + 2ghB.u 2ghC.2u2 ghD.gh 2u2

3. If is the maximum range of a projectile, then the range ( R ) of the projectile when

fired at an angle of,with the same initial velocity would be[]

A.2RB.3 RC. 1 RD.1 R

8 max

max2 max4max

4.Rate of change of displacement of a body is called[]

A. AccelerationB. velocityC. momentumD. none of the above

5.The product of mass and velocity of a body is called[]

A. AccelerationB. velocityC. MomentumD. none of the above

6.If a body is moving in a straight line, the motion of the body is called____[]

A. RectilinearB. rotationalC. curvilinearD. none of the above.

7.A force P of high magnitude acts on a body for a small interval of timet. The force P is called_________.

[]

A. Impulsive forceB. kinetic energy of the bodyC. impulseD. none of the above

8. Energy lost by a body (of mass m and moving with a velocity V) when it strikes another body

(of mass M at rest) due to impact is equal to_____.A.mv2+mB.mv2 (m + M 1) C.

m + M

2g2g

mv2[]

m

D. none of the above

2gm + M

9.Tension in a cable supporting a lift, when lift is going up is equal to_____.[]

A. W 1fB. W 1+fC. W (W-)D. W (g +)

gg

10. The work done by a force or moment acting on a body during the virtual displacement of the body

is known as___________.[]

A. Virtual workB. Actual workC. Imaginary work D. None of the above.

11. The horizontal range of particle is maximum when angle of projectile is ______________.

12. If a body is moving with a uniform acceleration (a), then final velocity (V) of the body after time t is equal to ______________

13. If the weight m2 in Figure is resting on a rough horizontal plane having coefficient of friction , then the acceleration is equal to_________.

14. A light string passes over a smooth, weightless pulley and has weights 40N and 60N Attached to its end as shown in Figure .The tension in string will be________

15. A tower is of height 100 m. A stone is thrown up from the foot of water with a velocity of 20m/s and at the same time another stone is dropped from the top of the tower. The two stones will meet after____________ 16. A fly wheel starting from rest and accelerating uniformly performs 20 revolutions in 4 seconds.The angular velocity of flywheel after 8 seconds would be______ 17. A stone dropped into a well is heard to strike the water after 4 seconds.If the velocity of Sound is 350 m/s,the depth of well would be___________

18. The expression represents_____________.

19. In an inelastic allesion between two bodies, the physical quantity that is conserved is __________

20. The imaginary differential displacement that is possible but does not take place under action of forces is __________

UNIT V

PART-A1. Give mathematical definitions of velocity and acceleration. 2. A Car traverses half of a distance with a velocity of 40 Kmph and the remaining half of distance with a velocity of 60 Kmph. Find the average velocity. 3. Define friction and classify its types. 4. Classify the types of friction. 5. Define Limiting friction. 6. Define coefficient of static friction. 7. State coulombs laws of dry friction. 8. Define rolling resistance. 9. What is coefficient of rolling resistance? 10. Define coefficient of friction and express its relationship with angle of friction. 11. If x=3.5t3 7 t2, determine acceleration, velocity and position of the particle, when t = 5 sec. 12.Consider a wheel rolling on a straight track. Illustrate the characteristics of general plane motion. 12. Write work energy equation of rigid body. Mention the meaning for all parameters used in the equation. 13. What us general plane motion? Give some examples. 14. Define Limiting friction. 15. 16.Define Co-efficient of friction and angle of friction 16. Define coulombs laws of dry friction. 17. Define impending motion. 19.Define angle of repose 20.Define cone of friction. 18. Define the following terms i) Ladder friction. ii) Wedge friction iii) Screw friction iv) Belt friction. PART-B1. Block (2) rests on block (1) and is attached by a horizontal rope AB to the wall as shown in fig. What force P is necessary to cause motion of block (1) to impend? The co-efficient of friction between the blocks is and between the floor and block (1) is 1/3. Mass of blocks (1)and(2) are 14kg and 9 kg respectively

2. Block A weighing 1000 N rests on a rough inclined plane whose inclination to the horizontal is 45. It is connected to another block B, weighing 3000 N rests on a rough horizontal plane by a weightless rigid bar inclined at an angle of 30 to the horizontal as shown in fig. Find the horizontal force required to be applied to the block B just to move the block A in upward direction. Assume angle of friction as 15 at all surfaces where there is sliding.

3. A 7m long ladder rests against a vertical wall, with which it makes an angle of 45 and on a floor. If a man whose weight is one half that of the ladder climbs it, at what distance along the ladder will he be, when the ladder is about to slip? Take coefficient of friction between the ladder and the wall is 1/3 and that between the ladder and the floor is .

4. In a screw jack, the pitch of the square threaded screw is 5.5 mm and means diameter is 70 mm. The force exerted in turning the screw is applied at the end of lever 210 mm long measured from the axis of the screw. If the co-efficient of friction of the screw jack is 0.07. Calculate the force required at the end of the lever to (i) raise a weight of 30 KN (ii) lower the same weight. 5. An effort of 200 N is required just to move a certain body up an inclined plane of angle 15, the force is acting parallel to the plane. If the angle of inclination of the plane is made 20, the effort required being again parallel to the plane, is found to be 230 N. Find the weight of the body and coefficient of friction. 6. Find the force P inclined at an angle of 32 to the inclined plane making an angle of 25 degree with the horizontal plane to slide a block weighing 125 KN (i) up the inclined plane (ii) Down the inclined plane, when P = 0.5. Objective

I. Choose the correct alternative:

1.The velocity-time graph of a uniform accelerated body is a[]

A. circleB. Parabola C. Straight line. D. Hyperbola.

2.The angular velocity of a rotating body is expressed in[]

A. revolutions per minuteB. radians per second

C. both rev per min and rad per secD. none of the above

3. Two bodies of masses 2m and m have their KE in the ratio 8:1 then their ratio

of momentais[]

A. 1:1B. 2:1C. 4:1D. 8:1

4. A projectile will cover the maximum vertical distance in a minimum time when the angle of

projection is[]

A. 300B. 450C. 600D. 900

5.Which of the following remains constant during flight of a projectile?[]

A. vertical component of velocityB. horizontal component of velocity

C. angle of projectileD. sum of its kinetic energy and potential energy

6. Inertia force opposite to the direction of motion is placed on the free body diagram in which of

the following method[]

A. Impulse-momentum B. D Alemberts C. Work-energyD. Virtual work

7. Minimum coefficient of friction to prevent slipping of a solid cylinder when it rolls

On an inclined plane is ____tan []

A. 1/3B. C. 2/3.D.none of the above.

8.Unit of energy is ______[]

A. NewtonB. JouleC. wattD. none of the above.

9.Axis of motion of body is considered _____ in initial direction of motion.[]

A. PositiveB. negativeC. can not be determinedD. none of the above

10. A body of mass 2 kg is thrown up vertically with a kinetic energy of 49J .If the acceleration due to

gravity is 9.8mps2,the height at which the kinetic energy of the body becomes half its originalvalue is given by[]

A. 50mB. 25mC. 12.5mD. 10m

AI. Fill in the Blanks

11. The rate of change of displacement is ______

12. The position of a body wrt time is given by x = 2 t3 6t2 +12 t +6. At t=0 ,acceleration Is ___________

13. The instantaneous centre is a point which is always _________.

14. The kinetic energy of a body of mass m and velocity v is ______

15. If a body is projected downwards then acceleration of the body is _________

16. The work done by a force in an inextensible cord connecting two bodies is always ________

17.The work done isif the displacements or forces acting on a body are virtual.

18. The angle of projection of a projectile for which the horizontal range and the maximum height are equal is

19. A block A slides down a smooth inclined plane when released from top. While another similar block B falls freely from the same point. Which block reaches the ground first ______

20. The path of projectile is