Forces and Moments: Master the Fundamentals of Engineering Mechanics

Question 1

What is a unit vector that specifies a direction in space called?

Accepted Answer

A vector

Answer

A scalar

Answer

A moment

Answer

A force

Question 2

Which of the following is not a characteristic of a couple?

Accepted Answer

It has a net force.

Answer

It consists of two parallel forces.

Answer

The forces are equal in magnitude but opposite in direction.

Answer

The forces act on the same line of action.

Question 3

The resultant force of two forces acting in the same direction is:

Accepted Answer

Equal to the sum of the two forces

Answer

Equal to the difference of the two forces

Answer

Zero

Answer

Dependent on the angle between the two forces

Question 4

What is the purpose of a free body diagram?

Accepted Answer

To show the forces acting on an object in isolation

Answer

To show all the forces acting in a system

Answer

To show the displacement of an object over time

Answer

To show the velocity of an object over time

Question 5

The resultant force of a system of forces is the:

Accepted Answer

Vector sum of all the forces

Answer

Scalar sum of all the forces

Answer

Average of all the forces

Answer

Smallest of all the forces

Question 6

The centroid of a body is the point where:

Accepted Answer

The mass of the body is concentrated

Answer

The weight of the body acts

Answer

The resultant force of the body acts

Answer

The body is in equilibrium

Question 7

Moment of inertia is a measure of:

Accepted Answer

The resistance of an object to angular acceleration

Answer

The resistance of an object to linear acceleration

Answer

The mass of an object

Answer

The force applied to an object

Question 8

Shear stress is a force that:

Accepted Answer

Acts parallel to the surface of a body

Answer

Acts perpendicular to the surface of a body

Answer

Causes bending

Answer

Causes rotation

Question 9

A 10 kg block is stationary on a horizontal surface with a coefficient of friction of 0.2. What is the minimum horizontal force needed to start moving the block?

Accepted Answer

20 N

Answer

10 N

Answer

40 N

Question 10

A couple consists of:

Accepted Answer

Two equal and opposite forces acting at a distance

Answer

Two unequal and opposite forces acting at a distance

Answer

Three forces acting at the same point

Answer

Two forces acting perpendicular to each other

Question 11

The SI unit of moment is:

Accepted Answer

Newton-meter

Answer

Newton

Answer

Kilogram

Answer

Joule

Question 12

A force of 50 N is applied to a lever at a distance of 1.5 m from the fulcrum. What is the mechanical advantage of the lever?

Accepted Answer

3.33

Answer

1.5

Answer

0.67

Answer

2.0

Question 13

A distributed load of 1000 N/m acts on a 5 m beam. What is the total force acting on the beam?

Accepted Answer

5000 N

Answer

1000 N

Answer

2000 N

Answer

10000 N

Question 14

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

Accepted Answer

Resultant force

Answer

Contact force

Answer

Gravitational force

Answer

Magnetic force

Question 15

A couple is characterized by:

Accepted Answer

Zero net force and non-zero moment

Answer

Non-zero net force and non-zero moment

Answer

Zero net force and zero moment

Answer

Non-zero net force and zero moment

Question 16

The resultant of two concurrent forces acting at a point is a:

Accepted Answer

Single force with the vector sum of their magnitudes

Answer

Single force with the vector difference of their magnitudes

Answer

Two forces acting in the same direction

Answer

Two forces acting in opposite directions

Question 17

A force of 10 N acts on a point A. The moment of this force about a point B, which is 2 m away from A, is:

Accepted Answer

20 Nm

Answer

0 Nm

Answer

10 Nm

Answer

5 Nm

Question 18

The center of mass of a system of particles is the point where the:

Accepted Answer

Resultant force acting on the system is zero

Answer

Vector sum of the moments acting on the system is zero

Answer

Total weight of the system is concentrated

Answer

System is most stable

Question 19

A truss is a structure that is designed to:

Accepted Answer

Transmit loads

Answer

Support its own weight

Answer

Resist deformation

Answer

Store energy

Question 20

Which of the following is a fundamental principle of mechanics?

Accepted Answer

Newton's second law of motion

Answer

Law of conservation of energy

Answer

Law of superposition

Answer

Principle of virtual work

Question 21

A moment is a:

Accepted Answer

Force that causes rotation

Answer

Force that acts parallel to a surface

Answer

Force that acts perpendicular to a surface

Answer

Force that causes displacement

Question 22

What is the net force acting on a rigid body in equilibrium?

Accepted Answer

Zero

Answer

Non-zero constant

Answer

Varies with time

Answer

Depends on the body's mass

Question 23

A couple is a system of:

Accepted Answer

Two forces acting in opposite directions with equal magnitudes

Answer

Two forces acting in the same direction

Answer

Two forces acting in opposite directions with different magnitudes

Answer

Two forces acting perpendicular to each other

Question 24

What is the cross product of two vectors used to calculate?

Accepted Answer

A vector perpendicular to both vectors

Answer

A vector parallel to both vectors

Answer

A vector with a magnitude equal to the product of the magnitudes of the two vectors

Answer

A vector with a direction equal to the sum of the directions of the two vectors

Question 25

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

Accepted Answer

Moment

Answer

Tension

Answer

Compression

Answer

Shear

Question 26

Which of the following is the resultant of a system of parallel forces?

Accepted Answer

A single force

Answer

A couple

Answer

A moment

Answer

Zero

Question 27

Which of the following is **not** a method for analyzing forces and moments?

Accepted Answer

Numerical simulations

Answer

Free body diagrams

Answer

Equilibrium equations

Answer

Graphical methods

Question 28

Which of the following is correctly defined as a force?

Accepted Answer

A push or pull that acts on an object

Answer

A tendency to cause an object to rotate

Answer

A quantity that measures the inertia of an object

Answer

A change in the velocity of an object

Question 29

A couple is a system of forces that:

Accepted Answer

Has a non-zero net torque

Answer

Has a non-zero net force

Answer

Consists of two parallel forces

Answer

Acts on a single point

Question 30

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

Accepted 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 line connecting the point to the point of application of the force

Answer

The product of the force and the mass of the object on which the force is acting

Answer

The product of the force and the acceleration of the object on which the force is acting

Question 31

A couple is defined as a system of forces that:

Accepted Answer

Produces a net moment but no net force

Answer

Produces a net force but no net moment

Answer

Produces both a net force and a net moment

Answer

Produces neither a net force nor a net moment

Question 32

The resultant force of a system of forces acting on a rigid body is:

Accepted Answer

The vector sum of all the forces

Answer

Always zero

Answer

Always perpendicular to the net moment about any point

Answer

Proportional to the number of forces

Question 33

Identify the option that is not a type of force.

Accepted Answer

Velocity

Answer

Tensile force

Answer

Compressive force

Answer

Shear force

Question 34

Explain the resultant force of a system of forces acting on a rigid body.

Accepted Answer

The vector sum of all the forces acting on the body

Answer

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

Answer

The force that creates the greatest moment on the body

Answer

The force that is perpendicular to the plane of action of the other forces

Question 35

Describe the center of gravity of a body.

Accepted Answer

The point where the resultant force of gravity acts

Answer

Always located at the geometric center of the body

Answer

Always located below the geometric center of the body

Answer

Independent of the shape and mass distribution of the body

Question 36

Identify the unit of measurement for moment.

Accepted Answer

Newton-meter

Answer

Newton

Answer

Meter

Answer

Kilogram

Question 37

Which of the following is the definition of a couple?

Accepted Answer

Two equal and opposite forces acting at different points on a rigid body

Answer

Two forces acting at the same point in the same direction

Answer

Two forces acting at different points in the same direction

Answer

Two forces acting at the same point in opposite directions

Question 38

A rigid body is said to be in equilibrium if:

Accepted Answer

The sum of the forces acting on it is zero and the sum of the moments about any point is also zero

Answer

The sum of the forces acting on it is not zero but the sum of the moments about any point is zero

Answer

The sum of the moments about any point is zero but the sum of the forces acting on it is not zero

Answer

Neither the sum of the forces acting on it nor the sum of the moments about any point is zero

Question 39

In the International System of Units (SI), the unit of force is the:

Accepted Answer

Newton

Answer

Joule

Answer

Pascal

Answer

Watt

Question 40

Which of the following is NOT considered a classification of forces?

Accepted Answer

Kinetic energy

Answer

Contact force

Answer

Body force

Answer

Frictional force

Question 41

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

Accepted Answer

The cross product of the force vector and the position vector from the point to the line of action of the force

Answer

The dot product of the force vector and the position vector from the point to the line of action of the force

Answer

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

Answer

The sum of all moments acting on the point

Question 42

A couple is defined as:

Accepted Answer

Two parallel forces acting in opposite directions with equal magnitudes

Answer

Two intersecting forces acting in different directions with equal magnitudes

Answer

Two forces acting on the same line of action but in opposite directions

Answer

Three forces acting in the same plane but not collinear

Question 43

A rigid body is in equilibrium if:

Accepted Answer

The net force and 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

Answer

The body is at rest

Question 44

Which of the following force systems is self-equilibrating?

Accepted Answer

Two equal and opposite forces acting on the same line of action

Answer

Two equal and opposite forces acting on different lines of action

Answer

Three equal and opposite forces acting on non-collinear lines of action

Answer

Four equal and opposite forces acting on non-coplanar lines of action

Question 45

The centroid of a triangle is located:

Accepted Answer

At the intersection of the medians

Answer

At the midpoint of the longest side

Answer

At the geometric center of the triangle

Answer

At the point where all three altitudes intersect

Question 46

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

Accepted Answer

Resultant force

Answer

Contact force

Answer

Non-contact force

Answer

External force

Question 47

A couple is characterized by:

Accepted Answer

Two equal and opposite forces acting on different lines of action

Answer

Two equal and opposite forces acting on the same line of action

Answer

Two unequal and opposite forces acting on the same line of action

Answer

Two unequal and opposite forces acting on different lines of action

Question 48

The resultant force of a set of concurrent forces is:

Accepted Answer

A single force that produces the same effect as the original forces

Answer

A force that is equal to the sum of the original forces

Answer

A force that is opposite to the sum of the original forces

Answer

A force that is perpendicular to the sum of the original forces

Question 49

A rigid body is in equilibrium when:

Accepted Answer

Both the sum of all forces and moments acting on it is zero

Answer

The sum of all forces acting on it is zero

Answer

The sum of all moments acting on it is zero

Answer

The resultant force and moment acting on it are equal and opposite

Question 50

The SI units of specific weight are:

Accepted Answer

N/m^3

Answer

N/m

Answer

N/m^2

Answer

N/kg