Force Systems: Master the Fundamentals of Engineering Mechanics

Question 1

Which of the following is NOT a type of force system?

Accepted Answer

Equilibrium

Answer

Concurrent

Answer

Non-concurrent

Answer

Parallel

Question 2

Which of the following is NOT a fundamental type of force?

Accepted Answer

Torque

Answer

Tensile

Answer

Compressive

Answer

Centripetal

Question 3

The resultant force of a system of forces is the single force that:

Accepted Answer

Produces the same effect as the vector sum of the individual forces.

Answer

Is equal in magnitude but opposite in direction to the sum of the forces.

Answer

Acts perpendicular to all the individual forces.

Answer

Has the same moment as the resultant moment of the individual forces.

Question 4

The moment of a force about a point is a measure of:

Accepted Answer

The force's magnitude multiplied by its perpendicular distance from the point.

Answer

The force's ability to rotate an object about the point.

Answer

The force's direction relative to the point.

Answer

The force's effect on the point itself.

Question 5

A system of forces is in equilibrium if:

Accepted Answer

The resultant force and resultant moment are both zero.

Answer

The sum of the forces and the sum of the moments are both zero.

Answer

The magnitude of the resultant force is equal to the magnitude of the resultant moment.

Answer

The direction of the resultant force is perpendicular to the direction of the resultant moment.

Question 6

A torque wrench is primarily used to measure:

Accepted Answer

Torque

Answer

Force

Answer

Moment of inertia

Answer

Angular velocity

Question 7

The principle of virtual work is used to:

Accepted Answer

Analyze the equilibrium conditions of a system.

Answer

Calculate the forces acting on a system.

Answer

Determine the displacement of a system.

Answer

Predict the stability of a system.

Question 8

Which of the following is **not** a force?

Accepted Answer

Volume

Answer

Contact force

Answer

Field force

Answer

Gravitational force

Question 9

What is the magnitude of the resultant force acting on a particle in equilibrium?

Accepted Answer

Zero

Answer

Non-zero

Answer

Cannot be determined without additional information

Answer

Depends on the direction of the forces

Question 10

What is the difference between a scalar and a vector quantity?

Accepted Answer

A scalar quantity has magnitude only, while a vector quantity has both magnitude and direction

Answer

A vector quantity has magnitude only, while a scalar quantity has both magnitude and direction

Answer

Scalar quantities are always positive, while vector quantities can be positive or negative

Answer

Vector quantities are always positive, while scalar quantities can be positive or negative

Question 11

Which of the following physical quantities is a vector?

Accepted Answer

Force

Answer

Distance

Answer

Mass

Answer

Time

Question 12

What is the numerical value of the resultant force acting on a body?

Accepted Answer

The sum of all forces acting on the body

Answer

The difference between the largest and the smallest forces acting on the body

Answer

The average of all forces acting on the body

Answer

The force with the largest magnitude

Question 13

What is the moment of a force about a point?

Accepted Answer

The product of the force and the perpendicular distance from the point to the line of action of the force

Answer

The product of the force and the distance from the point to the line of action of the force

Answer

The product of the force and the angle between the force and the distance from the point to the line of action of the force

Answer

The product of the force and the time of application of the force

Question 14

Under which condition is a body in equilibrium?

Accepted Answer

Both the resultant force and the resultant moment are zero

Answer

The resultant force acting on the body is zero

Answer

The resultant moment about any point is zero

Answer

The body is moving at a constant velocity

Question 15

What is a couple?

Accepted Answer

A force system with a zero resultant moment

Answer

A force system with a zero resultant force

Answer

A force system with a non-zero resultant force and a zero resultant moment

Answer

A force system with a non-zero resultant force and a non-zero resultant moment

Question 16

What is a truss?

Accepted Answer

A structure made up of members connected by pins or hinges

Answer

A structure made up of members connected only at their endpoints

Answer

A structure made up of members connected by rigid joints

Answer

A structure made up of members connected by any type of joint

Question 17

When two parallel forces act in the same direction, what is the resultant force?

Accepted Answer

The sum of the two forces

Answer

The difference of the two forces

Answer

A force perpendicular to the two forces

Answer

A force parallel to the two forces with a smaller magnitude

Question 18

Define the moment of a force about a point.

Accepted Answer

The product of the force and the distance from the point to the force's line of action

Answer

The product of the force and the time it acts

Answer

The product of the force and the point's velocity

Answer

The product of the force and the point's acceleration

Question 19

For a rigid body to be in equilibrium, which conditions must be met?

Accepted Answer

Both (A) and (B) are required

Answer

The total force acting on the body must be zero

Answer

The total moment acting on the body must be zero

Answer

Neither (A) nor (B) is required

Question 20

Which theorem is not related to force systems?

Accepted Answer

Pythagorean theorem

Answer

Varignon's theorem

Answer

Principle of moments

Answer

Wrenches theorem

Question 21

Explain the significance of a body's moment of inertia.

Accepted Answer

It measures the body's resistance to rotation

Answer

It determines the body's mass

Answer

It determines the body's velocity

Answer

It determines the body's acceleration

Question 22

The resultant force of a system of forces acting on a particle is:

Accepted Answer

The vector sum of all the forces

Answer

The vector difference of all the forces

Answer

Zero

Answer

The average of all the forces

Question 23

Which of the following is a free-body diagram?

Accepted Answer

A diagram that shows all the forces acting on an object

Answer

A diagram that shows the object in motion

Answer

A diagram that shows the object at rest

Answer

A diagram that shows the object in equilibrium

Question 24

The efficiency of a machine is:

Accepted Answer

The ratio of output work to input work

Answer

The ratio of input work to output work

Answer

The difference between output work and input work

Answer

The sum of output work and input work

Question 25

The coefficient of friction is:

Accepted Answer

A measure of the roughness of a surface

Answer

A measure of the force required to overcome friction

Answer

A measure of the energy lost due to friction

Answer

A measure of the velocity of a sliding object

Question 26

Which of the following statements about forces is NOT true?

Accepted Answer

Forces are always perpendicular to the surface they act on.

Answer

Forces are vector quantities.

Answer

Forces can act at any point on a body.

Answer

Forces can either be pushes or pulls.

Question 27

For a rigid body in translation, the equilibrium equation is:

Accepted Answer

ΣF = 0

Answer

ΣM = 0

Answer

ΣF = ma

Answer

ΣM = Iα

Question 28

For a rigid body in rotation, the equilibrium equation is:

Accepted Answer

ΣM = 0

Answer

ΣF = 0

Answer

ΣF = ma

Answer

ΣM = Iα

Question 29

The resultant force of a system of forces acting on a particle is:

Accepted Answer

The single force that produces the same effect as all the forces acting together.

Answer

The sum of the magnitudes of all the forces.

Answer

The average of the magnitudes of all the forces.

Question 30

A rigid body is in equilibrium if:

Accepted Answer

The net force and the net moment acting on it are both zero.

Answer

The net force acting on it is zero.

Answer

The net moment acting on it is zero.

Question 31

A system of forces acting on a rigid body produces a clockwise moment of 10 Nm and a counterclockwise moment of 5 Nm about a point. Is the body in equilibrium?

Accepted Answer

No

Answer

Equilibrium is not possible with a system of moments.

Answer

Yes

Answer

Cannot be determined

Question 32

A force of 100 N acts on a body at an angle of 30 degrees to the horizontal. What is the horizontal component of the force?

Accepted Answer

86.6 N

Answer

173.2 N

Answer

100 N

Answer

50 N

Question 33

For a beam of length 2L supported at its ends and subjected to a uniformly distributed load of intensity w, at what point along the beam does the maximum bending moment occur?

Accepted Answer

L/2

Answer

L/4

Answer

L

Answer

2L

Question 34

Define shear force at a section of a beam.

Accepted Answer

The algebraic sum of the transverse forces acting on either side of the section.

Answer

The algebraic sum of the moments acting on either side of the section.

Answer

The resultant force acting on the section.

Question 35

Describe the primary structural components of a truss.

Accepted Answer

Rigid members connected at their ends.

Answer

Flexible members connected at their ends.

Answer

Flexible members connected at their centers.

Answer

Rigid members connected at their midpoints.

Question 36

The method of sections is primarily used to determine:

Accepted Answer

The internal forces in members of a truss.

Answer

The deflection of a truss.

Answer

The external forces acting on a truss.

Answer

The reactions at the supports of a truss.

Question 37

Which of these is NOT a recognized classification of force systems in mechanics?

Accepted Answer

Elastic force system

Answer

Coplanar force system

Answer

Parallel force system

Answer

Concurrent force system

Question 38

Two forces of equal magnitude but opposite directions act on an object. What is their resultant force?

Accepted Answer

Zero force

Answer

A force that is twice the magnitude of either of the two forces

Answer

A force equal to the sum of the two forces

Answer

A force equal to the difference of the two forces

Question 39

A moment, in the context of forces, is the measure of a force's tendency to:

Accepted Answer

Rotate an object around an axis

Answer

Translate an object in a straight line

Answer

Deform an object

Question 40

A rigid body is considered to be in equilibrium when:

Accepted Answer

The net force and net moment acting on it are both zero

Answer

The net moment acting on it is zero

Answer

The net force acting on it is zero

Question 41

Which of the following is a scalar quantity, meaning it only has magnitude?

Accepted Answer

Magnitude of a force

Answer

Direction of a force

Answer

Moment of a force

Answer

Position of a force

Question 42

A 10 N force is applied to a body 2 meters away from the pivot point. Calculate the moment of this force about the pivot point.

Accepted Answer

20 Nm

Answer

40 Nm

Answer

30 Nm

Answer

10 Nm

Question 43

Two forces, 10 N and 15 N, act on a body 5 meters apart. Determine the magnitude of the resultant force.

Accepted Answer

25 N

Answer

5 N

Answer

30 N

Answer

15 N

Question 44

For a body to be in equilibrium under the action of three forces, these forces must be:

Accepted Answer

Concurrent and coplanar

Answer

Concurrent but not coplanar

Answer

Coplanar but not concurrent

Answer

Neither concurrent nor coplanar

Question 45

A 10 N force acts on a body at a 30-degree angle to the horizontal. What is the horizontal component of this force?

Accepted Answer

8.66 N

Answer

5 N

Answer

10 N

Answer

14.43 N

Question 46

The resultant of a force system is best described as:

Accepted Answer

A single force that has the same effect on the object as the original force system.

Answer

The largest force in the system

Answer

The smallest force in the system

Question 47

The moment of a force about a point is measured in:

Accepted Answer

Newton-meters

Answer

Meters

Answer

Newtons

Answer

Kilograms

Question 48

A body is in equilibrium if:

Accepted Answer

The sum of the forces and moments acting on it is zero

Answer

The sum of the moments acting on it is zero

Answer

The sum of the forces acting on it is zero

Question 49

Which of the following is an example of a non-coplanar force system?

Accepted Answer

Forces acting on a tetrahedron

Answer

Forces acting on a square

Answer

Forces acting on a circle

Answer

Forces acting on a triangle

Question 50

The centroid of a force system is the point at which:

Accepted Answer

The resultant force acts

Answer

The moment of the system is zero

Answer

The weight of the system acts

Answer

The system is in equilibrium

Question 51

A system of forces is in equilibrium if:

Accepted Answer

The sum of the forces and the sum of the moments are both zero

Answer

The sum of the moments is zero

Answer

The sum of the forces is zero

Question 52

The moment of inertia of a body about an axis is:

Accepted Answer

A measure of the body's resistance to angular acceleration

Answer

A measure of the body's mass

Answer

A measure of the body's velocity