Free Practice Quiz Question List

9 Connected Bodies and Basic Mechanical Systems Online Quiz Questions

Use this free practice quiz with 20 questions to review 9 Connected Bodies and Basic Mechanical Systems, test your knowledge, and prepare for your next test or exam.

20 questions

Choose one

1 point

Which contact forces act on a body touching a smooth surface?

A
A normal force and a friction force
B
A normal force but no friction force
C
A friction force but no normal force
D
Neither a normal force nor a friction force

True or false

1 point

True or false: For a hanging body, the cable tension is always equal to the body's weight, even if the body is accelerating.

A
True
B
False

True or false

1 point

When drawing a free-body diagram for a system made of several connected bodies, include the forces that the bodies exert on one another inside the system.

A
True
B
False

Choose one

1 point

You combine two connected bodies into one system to find the system's motion. How should you treat forces between the two bodies on the system-level free-body diagram?

A
Include all cable tensions and contact forces between parts, because every force must appear on every free-body diagram.
B
Omit forces internal to the chosen system and include forces exerted on it by its surroundings.
C
Omit both internal forces and external support reactions.
D
Replace every external force with the weight of the entire system.

Choose one

1 point

A single taut cable passes over one fixed pulley and connects two bodies. If each coordinate is positive in the direction that lengthens its cable segment, what does the cable constraint imply about their accelerations?

A
Their acceleration magnitudes are equal and their directions are opposite.
B
They have equal accelerations in the same direction.
C
One body's acceleration is twice the other's.
D
Their acceleration magnitudes are unrelated.

Choose all

1 point

Select all statements that describe a sound approach to analyzing connected bodies with separate free-body diagrams.

A
Draw a separate free-body diagram for each body whose motion or forces are being analyzed.
B
Put every force in the system on the free-body diagram of each individual body.
C
Use a consistent sign convention when writing the bodies' equations.
D
Assume the tension equals each body's weight before writing the equations.

Fill in the blank

1 point

For a taut, inextensible cable, write the total variable cable length as a .

Choose one

1 point

An ideal movable pulley attached to a stationary load of $200\,\text{N}$ is supported by two vertical segments of the same cable. What is the cable tension?

A
50 N
B
75 N
C
100 N
D
200 N

Choose all

1 point

Select all steps that belong in a reliable solution of a connected-body motion problem.

A
Choose positive directions and use them consistently.
B
Assume all connected bodies have the same acceleration magnitude.
C
Include each changing segment when expressing cable length.
D
Check the result's units and whether its sign agrees with the assumed directions.

Fill in the blank

1 point

In the described movable-pulley arrangement, the free end moves as far as the movable pulley, but in the opposite direction.

Open ended

1 point

An ideal fixed pulley connects two hanging masses, $m_1=2\,\text{kg}$ and $m_2=3\,\text{kg}$ . Take $m_2$ 's downward direction as positive and use $g=9.81\,\text{m/s}^2$ . Write the two force equations and the cable constraint, then determine the acceleration and state which way $m_2$ accelerates.

Choose one

1 point

When several connected bodies are treated as one system in a free-body diagram, what should be done with forces the bodies exert on one another?

A
They remain on the system FBD because each body has its own weight.
B
They cancel within the system and are omitted from its system-level FBD.
C
They are replaced by a single external tension force.
D
They must be included only when the system is in equilibrium.

True or false

1 point

A smooth contact can exert a normal force, but it does not exert a friction force.

A
True
B
False

Choose one

1 point

A single continuous, ideal cable passes over a frictionless, massless pulley. What can be concluded about the tension magnitudes on the two sides?

A
The tension is zero at the pulley because the cable changes direction.
B
The tension is greater on the side supporting the heavier body.
C
The tension has the same magnitude throughout the cable.
D
The tension equals the weight of each connected body.

Choose one

1 point

For a rigid body in planar static equilibrium, which set of equations is required?

A
Use force equations only, because moments are internal to a rigid body.
B
Use both force equations and a moment equation.
C
Use a moment equation only if the body is accelerating.
D
Use Newton’s second law for translation but omit the moment equation.

Choose one

1 point

A taut, inextensible cable passes over one fixed pulley and connects two bodies. Each coordinate is positive when its cable segment increases. Which acceleration constraint follows from the cable’s constant length?

A
$a_1+a_2=0$
B
$a_1-a_2=0$
C
$2a_1+a_2=0$
D
$a_1a_2=0$

Written response

1 point

After solving an acceleration equation using a chosen positive direction, you obtain a negative value. In what direction is the actual acceleration relative to that chosen direction?

Written response

1 point

In an ideal movable-pulley arrangement, the cable-length constraint is $x+2y=\text{constant}$ , where both coordinates are positive downward. If the load and movable pulley move downward by $0.15\,\text{m}$ , what is the free end’s displacement magnitude in centimetres?

Written response

1 point

A 4 kg body translates horizontally under a net horizontal force of 14 N. What is its horizontal acceleration in m/s^2?

Written response

1 point

Name one non-ideal pulley property that could cause the tensions on the two sides of a continuous cable to differ.