Crossbuck frame

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Question throws error:

Numbas Error: Error evaluating variable ab: other.isTemperature is not a function. (In 'other.isTemperature()', 'other.isTemperature' is undefined)

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map@[native code]
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promiseReactionJob@[native code]

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Question statement

{geogebra_applet('c3ambsph',[['ab',scalar(ab)],['bc',scalar(bc)],['θ',theta+'°'],['r',scalar(r)]])}

A {scalar(w)} {units[0]} cylinder {2 r} in diameter is lodged between two cross pieces which make an angle of {theta}° with each other as shown. The length of each cross piece is {ab} from A to B and {bc} from B to C. Assume that the weight and width of the cross pieces are negligable and that the floor is smooth.

Determine the tension in horizontal rope C-C'.

Give any introductory information the student needs.

			Name	Type	Generated Value

L	quantity	quantity(12, "ft")
ab	quantity	quantity(3, "ft")
bc	quantity	quantity(9, "ft")
theta	integer	80
W	quantity	quantity(385, "lbs")
r	quantity	quantity(2.3, "ft")
debug	boolean	false
units	list	[ "lb", "ft" ]
unit_sys	string	us

			Name	Type	Generated Value

Ay	quantity	quantity(192.5, "lbs")
FD	quantity	quantity(299.4768366706292906940035648409397692604, "lbs")
bd	quantity	quantity(2.741033262966682943448066476131636834329, "ft")
T	quantity	quantity(172.9, "lbs")

Automatically regenerate variables?

Name

Data type

Value

xxxxxxxxxx
 
qty(
  if(unit_sys='si', 
    random(2..4#0.2),
    random(6..14#2)),
  units[1])
​
​
​

JME function reference

Description

Describe what this variable represents, and list any assumptions made about its value.

Can an exam override the value of this variable?

Generated value: `quantity`

quantity(12, "ft")

← Depends on:

unit_sys
units

→ Used by:

Variable testing condition

Parts

Implications Choose several from a list
Reactions at A Gap-fill
1. Gap $A_x$ Engineering Accuracy with units
  Add
2. Gap $A_y$ Engineering Accuracy with units
  Add
Force at D Gap-fill
1. Gap D Engineering Accuracy with units
  Add
Tension Gap-fill
1. Gap distance Engineering Accuracy with units
  Add
2. Gap Tension Engineering Accuracy with units
  Add

Choose several from a list

Ask the student a question, and give any hints about how they should answer this part.

What can be concluded from the problem statement? (Check all true statements.)

Minimum marks

Maximum marks

(no maximum)

Show correct answer on reveal?

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Advanced settings

Number of display columns

Minimum answers

Maximum answers

(no maximum)

What to do if wrong number of answers selected:

Custom marking matrix?

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Marking method

For each choice, specify the number of marks to add or subtract when the student picks it.

Variable list of choices?

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$A_x = A_y$

Marks: Distractor Message:
$A_x = A'_x$

Marks: Distractor Message:
$A_x = 0$

Marks: Distractor Message:
$A_y =0$

Marks: Distractor Message:
$A_y = A'_y$

Marks: Distractor Message:
The object is symmetrical.

Marks: Distractor Message:
There are no horzontal reactions at the floor.

Marks: Distractor Message:

Advice

Draw a free body diagram of the entire structure and find the reactions at A and A'. Because of symmetry it is apparent that A = A' = W/2.

Next, draw a free body diagram of the cylinder and determine the reaction forces at D and D' which support it.

$\Sigma F_y = 0$

$2 D_y = W$

$ 2 D \sin(\var{theta/2}°) = \var{w}$

Next, draw a free body diagram of cross piece ABC. Take moments about point B to determine the tension in the cable. Note that the perpendicular distance from B to D is $d_\perp = r/\tan(\var{theta/2}°) $

Give a worked solution to the whole question.

Use this tab to check that this question works as expected.

There was an error which means the tests can't run:

Part	Test	Passed?
Choose several from a list
Choose several from a list		Hasn't run yet
Gap-fill
Gap-fill		Hasn't run yet
Engineering Accuracy with units
Engineering Accuracy with units		Hasn't run yet
Engineering Accuracy with units
Engineering Accuracy with units		Hasn't run yet
Gap-fill
Gap-fill		Hasn't run yet
Engineering Accuracy with units
Engineering Accuracy with units		Hasn't run yet
Gap-fill
Gap-fill		Hasn't run yet
Engineering Accuracy with units
Engineering Accuracy with units		Hasn't run yet
Engineering Accuracy with units
Engineering Accuracy with units		Hasn't run yet

This question is used in the following exams:

Chapter 06 Exercises by Michael Proudman in Engineering Statics.
33. Frames and Machines 3 by Michael Proudman in Engineering Statics.
Homework 18: Frames by Sarah Sojka in Statics at Randolph College.
33. Frames and Machines 3 by William Haynes in Engineering Statics.
Chapter 6 Exercises by William Haynes in Engineering Statics.

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Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

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Checkpoint description

William Haynes commented 3 years, 3 months ago

William Haynes 3 years, 3 months ago

William Haynes 5 years, 9 months ago

William Haynes 5 years, 10 months ago

William Haynes 5 years, 10 months ago

William Haynes 6 years, 5 months ago

William Haynes 6 years, 5 months ago

William Haynes 6 years, 6 months ago

William Haynes 6 years, 6 months ago

William Haynes 6 years, 7 months ago

Error in variable testing condition

Error

Warning

Generated value: `quantity`

Parts

Choose several from a list

Advanced settings

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Crossbuck frame

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

William Haynes commented 3 years, 3 months ago

William Haynes 3 years, 3 months ago

William Haynes 5 years, 9 months ago

William Haynes 5 years, 10 months ago

William Haynes 5 years, 10 months ago

William Haynes 6 years, 5 months ago

William Haynes 6 years, 5 months ago

William Haynes 6 years, 6 months ago

William Haynes 6 years, 6 months ago

William Haynes 6 years, 7 months ago

Error in variable testing condition

Error

Warning

Generated value: quantity

Parts

Choose several from a list

Advanced settings

Generated value: `quantity`