Unit 1 - Practice Quiz

1 Which of the following is defined as the agency that tends to change the state of rest or of uniform motion of a body?

2 What is the SI unit of force?

3 A system of forces acting in the same plane is called:

4 What are concurrent forces?

5 When two or more forces act along the same line, they are called:

6 The process of splitting a force into two perpendicular components is known as:

7 If a force makes an angle with the horizontal x-axis, its horizontal component is:

8 The single force which produces the same effect as a system of forces is called:

9 The moment of a force about a point is defined as:

10 A couple consists of two forces that are:

11 The moment of a couple is equal to the product of one of the forces and the:

12 A body is said to be in equilibrium if the resultant of all forces acting on it is:

13 Which principle states that if three coplanar concurrent forces keep a body in equilibrium, each force is proportional to the sine of the angle between the other two?

14 A Free Body Diagram (FBD) is a sketch showing:

15 In a free body diagram, the weight of the body always acts:

16 For a general coplanar force system to be in equilibrium, how many independent equations of equilibrium are available?

17 For a system of coplanar concurrent forces in equilibrium, which equilibrium equation is NOT needed?

18 Varignon's theorem states that the moment of a resultant of two concurrent forces about any point is equal to:

19 The net force of a couple is:

20 Which of the following is a scalar quantity?

21 A body is treated as a 'rigid body' in engineering mechanics when:

22 According to the principle of transmissibility, the external effect of a force on a rigid body is unchanged if:

23 Which of the following defines a non-coplanar concurrent force system?

24 A force system consists of multiple forces whose lines of action are parallel to each other but act in different planes. This system is known as:

25 Two forces of N and N act at a point at an angle of to each other. What is the magnitude of their resultant?

26 Lami's Theorem is applicable only when a body is in equilibrium under the action of exactly:

27 Three forces , , and act on a particle in equilibrium. If the angle between and is and N, what is the value of the ratio in Lami's equation?

28 A force of 100 N acts at an angle of above the positive x-axis. What are its rectangular components (, )?

29 Varignon's Theorem of Moments states that:

30 A force of 50 N is applied perpendicularly to the end of a 2 m long wrench. What is the moment of the force about the pivot?

31 Which of the following statements about a 'couple' is true?

32 Two parallel forces of 20 N each act in opposite directions separated by a distance of 0.5 m. What is the magnitude of the couple?

33 A given force applied at a point on a rigid body can be replaced by:

34 For a system of coplanar non-concurrent forces to be in complete equilibrium, the necessary and sufficient conditions are:

35 A body is subjected to a system of forces such that the force polygon closes but the funicular (link) polygon does not close. What is the state of the body?

36 If three non-parallel coplanar forces keep a rigid body in equilibrium, their lines of action must:

37 When constructing a free body diagram (FBD) of a specific object, which of the following should be EXCLUDED?

38 A ladder rests against a smooth vertical wall and on a rough horizontal floor. In the free body diagram of the ladder, the reaction at the smooth wall is represented as:

39 A simply supported beam of length is subjected to a point load acting exactly at the center. What is the vertical reaction at each support?

40 A 100 N block rests on a rough horizontal plane. A horizontal force is applied to it. If the block is in equilibrium and the coefficient of static friction is , what is the maximum value of before motion impends?

41 Which of the following statements strictly defines a rigid body in the context of classical mechanics under arbitrary loading?

42 A spatial system of forces consists of non-coplanar, non-concurrent, and non-parallel forces. The general resultant of such a system can ALWAYS be reduced to which of the following?

43 Three coplanar concurrent forces , , and are in equilibrium. If the angle between and is , and between and is , which relationship accurately represents Lami's theorem?

44 A force N acts at a point m. What is the moment of this force about the point m?

45 A couple of magnitude acts on a rigid body. If the system is modified by moving the couple to a different location on the same plane and doubling the distance between its constituent forces while halving their magnitudes, what is the new resultant effect?

46 For a rigid body subjected to a general non-concurrent coplanar force system, which of the following sets of equilibrium equations is sufficient to guarantee complete equilibrium, provided the points A, B, and C are not collinear?

47 In a free body diagram of a rough uniformly heavy ladder leaning against a rough vertical wall and resting on a rough horizontal floor, how many distinct unknown reaction components exist at the points of contact before applying equilibrium equations?

48 A cantilever beam AB of length is fixed at A and subjected to a linearly varying distributed load which is $0$ at A and at B. What is the magnitude of the reaction moment at the fixed support A?

49 Varignon's Theorem states that the moment of a resultant of a system of concurrent forces about any point is equal to the algebraic sum of the moments of its components about the same point. This theorem is mathematically equivalent to the distributive property of which vector operation?

50 A continuous cable supports a frictionless pulley. If the tension on one side of the pulley is and on the other side is , and the cable is massless, which of the following is true in static equilibrium?

51 Forces and act on a particle. If the maximum resultant is and minimum resultant is , what is the magnitude of the resultant when and act at an angle of to each other?

52 When constructing a free body diagram for a rigid body connected by a pin joint (hinge) which is internally free to slide within a linear slot on a fixed surface, what reactions should be represented at the pin?

53 A system of forces consists of a force acting at the origin and a force acting at the point . This system is statically equivalent to:

54 According to the principle of transmissibility, a force acting on a rigid body can be moved along its line of action without changing its external effect. Which of the following is NOT preserved if this principle is applied to a deformable body?

55 A uniform semicircular rod of weight and radius is hinged at its lowest point and rests against a smooth vertical wall at one of its ends. What is the normal reaction at the wall if the plane of the semicircle is vertical?

56 For a system of parallel forces in a 3D space, which of the following represents the minimum number of scalar equations required to completely define its equilibrium?

57 A force is defined by its components N and N. It is translated to a new parallel coordinate system rotated by an angle where . What is the component of the force in the new coordinate system?

58 A heavy rigid cylinder rests in a V-shaped groove whose sides are inclined at angles and to the horizontal. Assuming all surfaces are perfectly smooth, what is the ratio of the normal reaction on the side inclined at to the normal reaction on the side inclined at ?

59 A two-force member is a body that is in equilibrium under the action of forces applied at exactly two points. For equilibrium to be maintained, these two forces must NOT necessarily be:

60 A force of $100$ N acts along the line . What is the magnitude of the equivalent couple required to move this force to an equivalent system passing through the origin?