FBD: Equations - mkraska/meclib GitHub Wiki

This is part of the FBD Example Question tutorial.

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Here we want to ask the student for input of the sums of forces and moments and check these against the system sketch. The feedback assumes that the correct answer can be represented without floating point numbers, because approximate equality of algebraic expressions is still to investigate.

image

The model answer is generated from the model answer system sketch.

Question variables

Add the extraction of the sums from the system sketch.

GG: sum_xyM(tansdata,tansnames,tansnames[i_P],a);

Question text

Add instructions and input and feedback specifiers.

**Gleichgewichtsbedingungen**

Geben Sie die Summe der Kräfte in \\\(x\\\)- und \\\(y\\\)-Richtung sowie die Summe der Momente um einen von Ihnen mit dem blauen Fadenkreuz gewählten Bezugspunkt an. Geprüft wird, ob das zu Ihrem Freischnitt passt.

<p>\(\Sigma F_x=\) [input:GGx](/mkraska/meclib/wiki/input:GGx) [validation:GGx](/mkraska/meclib/wiki/validation:GGx) [feedback:GGx](/mkraska/meclib/wiki/feedback:GGx)</p>
<p>\(\Sigma F_y=\) [input:GGy](/mkraska/meclib/wiki/input:GGy) [validation:GGy](/mkraska/meclib/wiki/validation:GGy) [feedback:GGy](/mkraska/meclib/wiki/feedback:GGy)</p>
<p>\(\Sigma M_\oplus=\) [input:GGM](/mkraska/meclib/wiki/input:GGM) [validation:GGM](/mkraska/meclib/wiki/validation:GGM) [feedback:GGM](/mkraska/meclib/wiki/feedback:GGM)</p>
  • Verify the question and update the form

Inputs GGx, GGy, GGM

Field Value
Input type Algebraic
Model answer GG[1],GG[2],GG[3]
Insert stars Insert stars for spaces only
Syntax hint Ausdruck
Hint attribute Placeholder
Forbid floats Yes
Show the validation Yes, compact

PRTs GGx, GGy, GGM

  • Feedback style: Compact
  • Set format of the feedback texts to HTML

Feedback variables

obj: stackjson_parse(objects);
GG: sum_xyM(obj,names,names[i_P],a);

Test for algebraic equivalence of

  • GGx versus GG[1]
  • GGy versus GG[2]
  • GGM versus GG[3]

Node 1 false feedback

Use these lines in the respective PRTs

{@fb_vars(GGx,GG[1],listofvars(GGx))@}
{@fb_vars(GGy,GG[2],listofvars(GGy))@}
{@fb_vars(GGM,GG[3],listofvars(GGM))@}

Check

  • Save and continue editing, Preview
  • Fill in correct responses, Check.