Free Practice Quiz Question List

5 Rigid-Body Equilibrium and Free-Body Diagrams Online Quiz Questions

Use this free practice quiz with 20 questions to review 5 Rigid-Body Equilibrium and Free-Body Diagrams, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

A free-body diagram of an entire connected assembly should show forces between parts inside that assembly as external forces. True or false?

A
True
B
False

Choose one

1 point

A body rests on a smooth horizontal roller support. Which reaction model should appear on its free-body diagram?

A
A horizontal force parallel to the surface
B
A vertical force normal to the surface
C
A horizontal force and a vertical force
D
A force and a reaction couple

Fill in the blank

1 point

When one part of a connected assembly is isolated, forces exerted on it by the other parts are to that part. On the FBD of the entire assembly, those same forces are .

Choose one

1 point

Which set of reaction components is appropriate for an ideal pin support in a two-dimensional problem?

A
One force along the pin
B
Two force components and a reaction couple
C
Two force components and no reaction couple
D
One force normal to the supporting surface

True or false

1 point

For a rigid body in planar static equilibrium, satisfying both force-balance equations is sufficient even if the net moment is nonzero. True or false?

A
True
B
False

Choose all

1 point

Select all statements that correctly describe idealized two-dimensional support reactions.

A
An ideal cable exerts tension along the cable.
B
A smooth surface exerts a force parallel to the surface.
C
A fixed support provides two force components and a reaction couple.
D
An ideal pin provides a reaction couple as well as two force components.

Written response

1 point

A weightless horizontal beam is 6 m long, pinned at A and supported by a roller on a horizontal surface at B. A 12 kN downward load acts 2 m from A. What is the upward roller reaction at B? Enter the magnitude in kN.

Fill in the blank

1 point

A force whose line of action passes through the chosen moment center produces moment about that point. In general, a force's moment depends on its distance from the point.

Choose all

1 point

Select all statements that describe a sound free-body diagram of a selected body or assembly.

A
Include the body's weight when it is relevant to the problem.
B
Show every interaction between parts inside the selected assembly.
C
Replace each removed support with the reaction components it can exert.
D
Omit applied loads if their magnitudes are already known.

Choose one

1 point

A weightless 4 m horizontal beam is pinned at A and supported by a roller at B on a horizontal surface. A 10 kN downward load acts 1 m from A. What is the roller reaction at B?

A
1.0 kN upward
B
2.5 kN upward
C
7.5 kN upward
D
10 kN upward

Open ended

1 point

Explain how to decide which interaction forces belong on a free-body diagram when first considering an entire connected assembly and then isolating just one part of it.

Choose one

1 point

A horizontal beam has a pin at A, a roller at B, and a downward point load between them. To find the roller reaction efficiently using moments, which moment center is most useful?

A
Choose a point where the applied load's moment is largest.
B
Choose the pin location, where both pin reaction lines of action pass.
C
Choose a point midway between the pin and roller so every reaction remains in the equation.
D
Choose the roller location so the roller reaction contributes to the moment equation.

Choose one

1 point

You isolate a connected assembly as one body for a free-body diagram. How should you represent forces between parts that are both included in that assembly?

A
Include every force between parts of the assembly as an external force.
B
Omit forces between parts within the assembly, but include forces exerted on it by its surroundings.
C
Omit all forces from supports because they are not part of the assembly.
D
Include only the assembly's weight and omit contact forces.

Choose one

1 point

When an ideal cable is removed from a body in a two-dimensional free-body diagram, what reaction should replace it?

A
A force normal to the cable, directed toward the body.
B
A force along the cable, directed toward the body.
C
A tension force along the cable, pulling away from the body.
D
Two force components and a reaction couple.

True or false

1 point

A free-body diagram should include relevant dimensions, in addition to the forces acting on the isolated body.

A
True
B
False

Written response

1 point

What distance from a point to a force's line of action determines the force's moment magnitude about that point?

Choose one

1 point

A smooth roller supports a body on a horizontal surface. Which reaction can the roller exert on the body?

A
A vertical force only.
B
A horizontal force only.
C
A horizontal and a vertical force, but no couple.
D
A horizontal and a vertical force plus a reaction couple.

Choose one

1 point

You assume a direction for an unknown support reaction, solve the equilibrium equations, and obtain a negative value. What does the sign indicate?

A
The support cannot exert a reaction.
B
The body is necessarily out of equilibrium.
C
The reaction magnitude should be replaced by zero.
D
The actual reaction points opposite to the assumed direction.

Written response

1 point

A horizontal, weightless 4 m beam is pinned at A and supported by a roller at B. A 10 kN downward load acts 1 m from A. Taking upward forces as positive, what is the vertical reaction $A_y$ at the pin? Enter your answer in kN.

Written response

1 point

For a statically indeterminate structure, what are the conditions relating deformations that can provide extra equations beyond planar equilibrium?