// Numbas version: exam_results_page_options
{"name": "Equilibrium of a rigid body: beam and pulley", "extensions": ["geogebra", "quantities"], "custom_part_types": [{"source": {"pk": 12, "author": {"name": "William Haynes", "pk": 2530}, "edit_page": "/part_type/12/edit"}, "name": "Angle quantity 2020", "short_name": "angle", "description": "<p>Adjusts all angles to 0 &lt; $\\theta$ &lt; 360.</p>\n<p>Accepts '&deg;' and 'deg' as units.</p>\n<p>Penalizes if not close enough or no units.</p>\n<p>90&deg; = -270&deg; = 450&deg;</p>", "help_url": "", "input_widget": "string", "input_options": {"correctAnswer": "plain_string(settings['expected_answer']) ", "hint": {"static": true, "value": ""}, "allowEmpty": {"static": true, "value": false}}, "can_be_gap": true, "can_be_step": true, "marking_script": "original_student_scalar:\nmatchnumber(studentAnswer,['plain','en'])[1]\n\nstudent_scalar:\nmod(original_student_scalar,360)\n\n\nstudent_unit:\nstudentAnswer[len(matchnumber(studentAnswer,['plain','en'])[0])..len(studentAnswer)]\n\ninterpreted_unit:\nif(trim(student_unit)='\u00b0','deg',student_unit)\n\ninterpreted_answer:\nqty(mod(student_scalar,360),'deg')\n\nclose:\nwithintolerance(student_scalar, correct_scalar,decimal(settings['close_tol']))\n\ncorrect_scalar:\nmod(scalar(settings['expected_answer']),360)\n\nright:\nwithintolerance(student_scalar, correct_scalar, decimal(settings['right_tol']))\n\ngood_unit:\nsame(qty(1,interpreted_unit),qty(1,'deg'))\n\nmark:\nassert(close,incorrect('Incorrect.');end());\nif(right,correct('Correct angle.'), set_credit(1 - settings['close_penalty'],'Angle is close.'));\nassert(good_unit,sub_credit(settings['unit_penalty'], 'Missing or incorrect units.'))", "marking_notes": [{"name": "original_student_scalar", "description": "<p>Retuns the scalar part of students answer (which is a quantity) as a number.</p>", "definition": "matchnumber(studentAnswer,['plain','en'])[1]"}, {"name": "student_scalar", "description": "<p>Normalize angle with mod 360</p>", "definition": "mod(original_student_scalar,360)\n"}, {"name": "student_unit", "description": "<p>matchnumber(studentAnswer,['plain','en'])[0] is a string \"12.34\"</p>", "definition": "studentAnswer[len(matchnumber(studentAnswer,['plain','en'])[0])..len(studentAnswer)]"}, {"name": "interpreted_unit", "description": "<p>Allows student to use degree symbol or 'deg' for units.</p>", "definition": "if(trim(student_unit)='\u00b0','deg',student_unit)"}, {"name": "interpreted_answer", "description": "A value representing the student's answer to this part.", "definition": "qty(mod(student_scalar,360),'deg')"}, {"name": "close", "description": "", "definition": "withintolerance(student_scalar, correct_scalar,decimal(settings['close_tol']))"}, {"name": "correct_scalar", "description": "<p>Normalize expected_answer with mod 360</p>", "definition": "mod(scalar(settings['expected_answer']),360)"}, {"name": "right", "description": "", "definition": "withintolerance(student_scalar, correct_scalar, decimal(settings['right_tol']))"}, {"name": "good_unit", "description": "", "definition": "same(qty(1,interpreted_unit),qty(1,'deg'))"}, {"name": "mark", "description": "This is the main marking note. It should award credit and provide feedback based on the student's answer.", "definition": "assert(close,incorrect('Incorrect.');end());\nif(right,correct('Correct angle.'), set_credit(1 - settings['close_penalty'],'Angle is close.'));\nassert(good_unit,sub_credit(settings['unit_penalty'], 'Missing or incorrect units.'))"}], "settings": [{"name": "expected_answer", "label": "Expected Answer", "help_url": "", "hint": "Expected angle as a quantity.", "input_type": "code", "default_value": "qty(30,'deg')", "evaluate": true}, {"name": "unit_penalty", "label": "Unit penalty", "help_url": "", "hint": "Penalty for not including degree sign or 'deg'.", "input_type": "percent", "default_value": "20"}, {"name": "close_penalty", "label": "Close Penalty", "help_url": "", "hint": "Penalty for close answer.", "input_type": "percent", "default_value": "20"}, {"name": "close_tol", "label": "Close", "help_url": "", "hint": "Angle must be $\\pm$ this many degrees to be marked close. &nbsp;&nbsp;", "input_type": "code", "default_value": "0.5", "evaluate": false}, {"name": "right_tol", "label": "Right ", "help_url": "", "hint": "Angle must be $\\pm$ this many degrees to be marked correct. &nbsp;", "input_type": "code", "default_value": "0.1", "evaluate": false}], "public_availability": "restricted", "published": false, "extensions": ["quantities"]}, {"source": {"pk": 19, "author": {"name": "William Haynes", "pk": 2530}, "edit_page": "/part_type/19/edit"}, "name": "Engineering Accuracy with units", "short_name": "engineering-answer", "description": "<p>A value with units marked right if within an adjustable % error of the correct value. &nbsp;Marked close if within a wider margin of error.</p>", "help_url": "", "input_widget": "string", "input_options": {"correctAnswer": "siground(settings['correctAnswer'],4)", "hint": {"static": true, "value": ""}, "allowEmpty": {"static": true, "value": true}}, "can_be_gap": true, "can_be_step": true, "marking_script": "mark:\nswitch( \n  right and good_units and right_sign, add_credit(1.0,'Correct.'),\n  right and good_units and not right_sign, add_credit(settings['C2'],'Wrong sign.'),\n  right and right_sign and not good_units, add_credit(settings['C2'],'Correct value, but wrong or missing units.'),\n  close and good_units, add_credit(settings['C1'],'Close.'),\n  close and not good_units, add_credit(settings['C3'],'Answer is close, but wrong or missing units.'),\n  incorrect('Wrong answer.')\n)\n\n\ninterpreted_answer:\nqty(student_scalar, student_units)\n\n\n\ncorrect_quantity:\nsettings[\"correctAnswer\"]\n\n\n\ncorrect_units:\nunits(correct_quantity)\n\n\nallowed_notation_styles:\n[\"plain\",\"en\"]\n\nmatch_student_number:\nmatchnumber(studentAnswer,allowed_notation_styles)\n\nstudent_scalar:\nmatch_student_number[1]\n\nstudent_units:\nreplace_regex('ohms','ohm',\n  replace_regex('\u00b0', ' deg',\n    replace_regex('-', ' ' ,\n      studentAnswer[len(match_student_number[0])..len(studentAnswer)])),\"i\")\n\ngood_units:\ntry(\ncompatible(quantity(1, student_units),correct_units),\nmsg,\nfeedback(msg);false)\n\n\nstudent_quantity:\nswitch(not good_units, \n       student_scalar * correct_units, \n       not right_sign,\n       -quantity(student_scalar, student_units),\n       quantity(student_scalar,student_units)\n)\n  \n\n\npercent_error:\ntry(\nscalar(abs((correct_quantity - student_quantity)/correct_quantity))*100  \n,msg,\nif(student_quantity=correct_quantity,0,100))\n   \n\nright:\npercent_error <= settings['right']\n\n\nclose:\nright_sign and percent_error <= settings['close']\n\nright_sign:\nsign(student_scalar) = sign(correct_quantity)", "marking_notes": [{"name": "mark", "description": "This is the main marking note. It should award credit and provide feedback based on the student's answer.", "definition": "switch( \n  right and good_units and right_sign, add_credit(1.0,'Correct.'),\n  right and good_units and not right_sign, add_credit(settings['C2'],'Wrong sign.'),\n  right and right_sign and not good_units, add_credit(settings['C2'],'Correct value, but wrong or missing units.'),\n  close and good_units, add_credit(settings['C1'],'Close.'),\n  close and not good_units, add_credit(settings['C3'],'Answer is close, but wrong or missing units.'),\n  incorrect('Wrong answer.')\n)\n"}, {"name": "interpreted_answer", "description": "A value representing the student's answer to this part.", "definition": "qty(student_scalar, student_units)\n\n"}, {"name": "correct_quantity", "description": "", "definition": "settings[\"correctAnswer\"]\n\n"}, {"name": "correct_units", "description": "", "definition": "units(correct_quantity)\n"}, {"name": "allowed_notation_styles", "description": "", "definition": "[\"plain\",\"en\"]"}, {"name": "match_student_number", "description": "", "definition": "matchnumber(studentAnswer,allowed_notation_styles)"}, {"name": "student_scalar", "description": "", "definition": "match_student_number[1]"}, {"name": "student_units", "description": "<p>Modify&nbsp;the&nbsp;unit portion of&nbsp;the student's answer by</p>\n<p>1. replacing \"ohms\" with \"ohm\" &nbsp;case insensitive</p>\n<p>2.&nbsp;replacing '-'&nbsp;with ' '&nbsp;</p>\n<p>3. replacing '&deg;' with ' deg'&nbsp;</p>\n<p>to allow answers like 10 ft-lb and 30&deg;</p>", "definition": "replace_regex('ohms','ohm',\n  replace_regex('\u00b0', ' deg',\n    replace_regex('-', ' ' ,\n      studentAnswer[len(match_student_number[0])..len(studentAnswer)])),\"i\")"}, {"name": "good_units", "description": "", "definition": "try(\ncompatible(quantity(1, student_units),correct_units),\nmsg,\nfeedback(msg);false)\n"}, {"name": "student_quantity", "description": "<p>This fixes the student answer for two common errors. &nbsp;</p>\n<p>If student_units are wrong&nbsp;&nbsp;- replace with correct units</p>\n<p>If student_scalar has the wrong sign - replace with right sign</p>\n<p>If student makes both errors, only one gets fixed.</p>", "definition": "switch(not good_units, \n       student_scalar * correct_units, \n       not right_sign,\n       -quantity(student_scalar, student_units),\n       quantity(student_scalar,student_units)\n)\n  \n"}, {"name": "percent_error", "description": "", "definition": "try(\nscalar(abs((correct_quantity - student_quantity)/correct_quantity))*100  \n,msg,\nif(student_quantity=correct_quantity,0,100))\n   "}, {"name": "right", "description": "", "definition": "percent_error <= settings['right']\n"}, {"name": "close", "description": "<p>Only marked close if the student actually has the right sign.</p>", "definition": "right_sign and percent_error <= settings['close']"}, {"name": "right_sign", "description": "", "definition": "sign(student_scalar) = sign(correct_quantity) "}], "settings": [{"name": "correctAnswer", "label": "Correct Quantity.", "help_url": "", "hint": "The correct answer given as a JME quantity.", "input_type": "code", "default_value": "", "evaluate": true}, {"name": "right", "label": "% Accuracy for right.", "help_url": "", "hint": "Question will be considered correct if the scalar part of the student's answer is within this % of correct value.", "input_type": "code", "default_value": "0.2", "evaluate": true}, {"name": "close", "label": "% Accuracy for close.", "help_url": "", "hint": "Question will be considered close if the scalar part of the student's answer is within this % of correct value.", "input_type": "code", "default_value": "1.0", "evaluate": true}, {"name": "C1", "label": "Close with units.", "help_url": "", "hint": "Partial Credit for close value with appropriate units. &nbsp;if correct answer is 100 N and close is &plusmn;1%,<br />99 &nbsp;N is accepted.", "input_type": "percent", "default_value": "75"}, {"name": "C2", "label": "No units or wrong sign", "help_url": "", "hint": "Partial credit for forgetting units or using wrong sign.<br />If the correct answer is 100 N, both 100 and -100 N are accepted.", "input_type": "percent", "default_value": "50"}, {"name": "C3", "label": "Close, no units.", "help_url": "", "hint": "Partial Credit for close value but forgotten units.<br />This value would be close&nbsp;if the expected units were provided. &nbsp;If the correct answer is 100 N, and close is &plusmn;1%,<br />99 is accepted.", "input_type": "percent", "default_value": "25"}], "public_availability": "always", "published": true, "extensions": ["quantities"]}], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Equilibrium of a rigid body: beam and pulley", "tags": ["angle from reference", "Mechanics", "mechanics", "pulley", "rigid body equilibrium", "Rigid body equilibrium", "Statics", "statics"], "metadata": {"description": "<p>Rigid body equilibrium problem. &nbsp;Easiest to solve by replacing forces on the perimiter of the pulley with equivalent forces at the axle.</p>", "licence": "Creative Commons Attribution-NonCommercial 4.0 International"}, "statement": "<p>{geogebra_applet('nnkbvxb8',[['L',scalar(L)],['ab',scalar(ab)],['r',scalar(r)/12],['alpha',alpha+'&deg;'],['theta',theta+'&deg;']])}</p>\n<p>{L} long beam $ABC$ supports a frictionless pulley with {r} radius&nbsp;at point $B$, located {ab} from the left end. Determine the reactions at $A$ and $C$ when it supports&nbsp;{W} weight $W$ as shown.</p>\n<p></p>\n<p></p>", "advice": "<p></p>\n<p><strong>Known</strong>: $L = \\var{l} \\qquad&nbsp;d = \\var{ab} \\qquad&nbsp;\\theta = \\var{theta}&deg; \\qquad \\alpha = \\var{alpha}&deg; \\qquad&nbsp;W = T = \\var{W}$</p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\n<li>Draw a free body diagram of the beam. &nbsp;It simplifies the solution to replace the forces of the rope on the pulley with equivalent forces at point $B$. The force at $C$ acts perpendicular to the surface the roller rests on.\n<p>{geogebra_applet('kggckbyp',[['L',scalar(L)],['ab',scalar(ab)],['r',scalar(r)/12],['alpha',alpha+'&deg;'],['theta',theta+'&deg;']])}</p>\n</li>\n<li>Take moments about point $A$ to find the reaction at $C$.\n<p style=\"text-align: center;\">$\\begin{align}\\Sigma M_A &amp;= 0&nbsp;\\\\+ C_y L+ &nbsp;T_y d - W d&amp;= 0 \\\\&nbsp;&nbsp;C_y &nbsp;&amp;=\\dfrac{ d (W - T \\cos \\theta)}{L} &nbsp;= \\var{display(Cy)}\\\\C &amp;= \\dfrac{C_y}{\\cos \\alpha} = \\var{display(magC)}\\end{align}$&nbsp;</p>\n</li>\n<li>Apply $F_x=0$ to find $A_x$.\n<p style=\"text-align: center;\">$\\begin{align}F_x&amp;=0\\\\A_x - T_x - C_x &amp;= 0 \\\\A_x &amp;= C_x + T_x\\\\A_x&amp;= C \\sin \\alpha + T \\sin \\theta&nbsp;= \\var{display(Ax)}\\end{align}$</p>\n</li>\n<li>Apply $\\Sigma F_y = 0$ to find $A_y$.\n<p style=\"text-align: center;\">$\\begin{align}F_y&amp;=0\\\\A_y&nbsp;+ C_y +&nbsp;T_y&nbsp;- W&nbsp; &amp;= 0 \\\\A_y &amp;= W&nbsp;-&nbsp;C_y -&nbsp;T_y\\\\A_y&amp;= W&nbsp;&nbsp;- C \\cos \\alpha - T \\cos \\theta= \\var{display(Ay)}\\end{align}$</p>\n</li>\n<li>Resolve $A_x$ and $A_y$ to get magnitude and direction of force $\\mathbf{A}$.\n<p style=\"text-align: center;\">$A = \\sqrt{(A_x)^2+(A_y)^2} = \\var{display(magA)}$</p>\n<p style=\"text-align: center;\">$\\phi = \\tan^{-1} \\left(\\dfrac{A_y}{A_x}\\right) = \\var{precround(dirA,2)}$&deg; &nbsp;from the positive <em>x</em>-axis.</p>\n</li>\n<li>Check with $\\Sigma \\mathbf{F} = 0$.\n<p style=\"text-align: center;\">$ \\mathbf{A} + \\mathbf{C}&nbsp;+ \\mathbf{W}&nbsp;+ \\mathbf{T}&nbsp;= 0$&nbsp;</p>\n<p style=\"text-align: center;\">$\\var{precround(vecA,2)} + \\var{precround(vecC,2)} + &nbsp;\\var{vecW} + \\var{precround(vecT,2)} = \\var{precround(sum,2)}$</p>\n</li>\n</ol>\n</li>\n</ol>", "rulesets": {}, "extensions": ["geogebra", "quantities"], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true}, "constants": [], "variables": {"r": {"name": "r", "group": "Ungrouped variables", "definition": "qty(random(12..24#2),'inch')", "description": "", "templateType": "anything", "can_override": false}, "ab": {"name": "ab", "group": "Ungrouped variables", "definition": "qty(random(2..10),'ft')", "description": "", "templateType": "anything", "can_override": false}, "vecT": {"name": "vecT", "group": "Unnamed group", "definition": "vector(cos(radians(90+theta)),sin(radians(90+theta))) scalar(W)", "description": "", "templateType": "anything", "can_override": false}, "vecW": {"name": "vecW", "group": "Unnamed group", "definition": "vector(0,-scalar(W))", "description": "", "templateType": "anything", "can_override": false}, "Cy": {"name": "Cy", "group": "Unnamed group", "definition": "ab * W *(1- cos(radians(theta)))/ L", "description": "", "templateType": "anything", "can_override": false}, "W": {"name": "W", "group": "Ungrouped variables", "definition": "qty(random(25..200#25),'lb')", "description": "", "templateType": "anything", "can_override": false}, "Ay": {"name": "Ay", "group": "Unnamed group", "definition": "W - magC cos(radians(alpha)) - T cos(radians(theta))", "description": "", "templateType": "anything", "can_override": false}, "dirC": {"name": "dirC", "group": "Unnamed group", "definition": "90+alpha", "description": "", "templateType": "anything", "can_override": false}, "theta": {"name": "theta", "group": "Ungrouped variables", "definition": "random(55..75#5)", "description": "", "templateType": "anything", "can_override": false}, "vecC": {"name": "vecC", "group": "Unnamed group", "definition": "vector(scalar(Cx),scalar(Cy))", "description": "", "templateType": "anything", "can_override": false}, "alpha": {"name": "alpha", "group": "Ungrouped variables", "definition": "random(30..45#5)", "description": "", "templateType": "anything", "can_override": false}, "Ax": {"name": "Ax", "group": "Unnamed group", "definition": "magC sin(radians(alpha)) + T sin(radians(theta))", "description": "", "templateType": "anything", "can_override": false}, "magA": {"name": "magA", "group": "Unnamed group", "definition": "qty(abs(vecA),'lb')", "description": "", "templateType": "anything", "can_override": false}, "dirA": {"name": "dirA", "group": "Unnamed group", "definition": "degrees(atan2(scalar(Ay),scalar(Ax)))", "description": "", "templateType": "anything", "can_override": false}, "Cx": {"name": "Cx", "group": "Unnamed group", "definition": "magC * (cos(radians(alpha+90)))", "description": "", "templateType": "anything", "can_override": false}, "vecA": {"name": "vecA", "group": "Unnamed group", "definition": "vector(scalar(Ax),scalar(Ay))", "description": "", "templateType": "anything", "can_override": false}, "T": {"name": "T", "group": "Ungrouped variables", "definition": "W", "description": "", "templateType": "anything", "can_override": false}, "magC": {"name": "magC", "group": "Unnamed group", "definition": "Cy/cos(radians(alpha))", "description": "", "templateType": "anything", "can_override": false}, "sum": {"name": "sum", "group": "Unnamed group", "definition": "vecA+vecC+vecW+vecT", "description": "", "templateType": "anything", "can_override": false}, "L": {"name": "L", "group": "Ungrouped variables", "definition": "qty(random(8..16),'ft')", "description": "", "templateType": "anything", "can_override": false}, "dir_C_from_X": {"name": "dir_C_from_X", "group": "Unnamed group", "definition": "qty(degrees(atan2(scalar(cy),scalar(cx))),'deg')", "description": "", "templateType": "anything", "can_override": false}, "debug": {"name": "debug", "group": "Ungrouped variables", "definition": "false", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "ab > r + qty(1,'ft') and ab < l-r- qty(2,'ft')", "maxRuns": 100}, "ungrouped_variables": ["L", "r", "ab", "alpha", "theta", "W", "T", "debug"], "variable_groups": [{"name": "Unnamed group", "variables": ["Cy", "magC", "Ax", "Ay", "magA", "dirA", "Cx", "vecA", "vecC", "vecW", "vecT", "sum", "dirC", "dir_C_from_X"]}], "functions": {"display": {"parameters": [["q", "quantity"]], "type": "string", "language": "jme", "definition": "string(siground(q,4))"}}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "gapfill", "useCustomName": true, "customName": "Reaction at C", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "interpreted_angle:  // a qty string corrected to standard angle\n  student_angle[2]  + student_angle[1] * student_angle[0] + student_units\n\nmagnitude:\n  studentAnswer[3]\n\nstudent_angle:\n  [mod(matchnumber(studentAnswer[0],['plain','en'])[1],360), // angle\n  [1,-1][indices(studentAnswer[1],[true])[0]],      // ccw = 1 cw = -1\n  [0,90,180,-90][indices(studentAnswer[2],[true])[0]]] // reference axis\n\nstudent_units:\n  studentAnswer[0][len(matchnumber(studentAnswer[0],['plain','en'])[0])..len(studentAnswer[0])]\n\ninterpreted_answers:\n  [interpreted_angle, studentAnswer[1], studentAnswer[2], studentAnswer[3]]\n\ngap_feedback (Feedback on each of the gaps):\n    map(\n        try(\n            let(\n                result, submit_part(gaps[gap_number][\"path\"],answer),\n                gap, gaps[gap_number],\n                name, gap[\"name\"],  \n                noFeedbackIcon, not gap[\"settings\"][\"showFeedbackIcon\"],\n                assert(name=\"\" or len(gaps)=1,feedback(translate('part.gapfill.feedback header',[\"name\": name])));\n                concat_feedback(filter(x[\"op\"]<>\"warning\",x,result[\"feedback\"]), if(marks>0,result[\"marks\"]/marks,1), noFeedbackIcon);\n                    result\n            ),\n            err,\n            fail(translate(\"part.gapfill.error marking gap\",[\"name\": gaps[gap_number][\"name\"], \"message\": err]))\n        ),\n        [gap_number,answer,index],\n        zip([3,0],[studentAnswer[3], interpreted_angle],[1,2])\n    )\n\n", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Determine the magnitude and direction of the reaction at the roller at $C$.</p>\n<p>Force $\\mathbf{C}$ has a magnitude of [[3]]&nbsp;</p>\n<p>acting at an angle of&nbsp;[[0]] measured&nbsp;[[1]]&nbsp;from the [[2]].</p>\n<p><span data-jme-visible=\"debug\"><strong>C</strong> = {magC}, angle={dirC}&deg;</span></p>", "gaps": [{"type": "angle", "useCustomName": true, "customName": "angleC", "marks": "10", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "settings": {"expected_answer": "dir_C_from_X", "unit_penalty": "20", "close_penalty": "20", "close_tol": "0.5", "right_tol": "0.2"}}, {"type": "1_n_2", "useCustomName": true, "customName": "sign", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "dropdownlist", "displayColumns": 0, "showCellAnswerState": true, "choices": ["CCW", "CW"], "matrix": [0, 0], "distractors": ["", ""]}, {"type": "1_n_2", "useCustomName": true, "customName": "ref", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "dropdownlist", "displayColumns": 0, "showCellAnswerState": true, "choices": ["+x axis", "+y axis", "-x axis", "-y axis"], "matrix": [0, 0, 0, 0], "distractors": ["", "", "", ""]}, {"type": "engineering-answer", "useCustomName": true, "customName": "magC", "marks": "10", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "settings": {"correctAnswer": "magC", "right": "0.2", "close": "1.0", "C1": "75", "C2": "50", "C3": "25"}}], "sortAnswers": false}, {"type": "gapfill", "useCustomName": true, "customName": "Reaction at A", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "interpreted_angle:  // a qty string corrected to standard angle\n  student_angle[2]  + student_angle[1] * student_angle[0] + student_units\n\nmagnitude:\n  studentAnswer[3]\n\nstudent_angle:\n  [mod(matchnumber(studentAnswer[0],['plain','en'])[1],360), // angle\n  [1,-1][indices(studentAnswer[1],[true])[0]],      // ccw = 1 cw = -1\n  [0,90,180,-90][indices(studentAnswer[2],[true])[0]]] // reference axis\n\nstudent_units:\n  studentAnswer[0][len(matchnumber(studentAnswer[0],['plain','en'])[0])..len(studentAnswer[0])]\n\ninterpreted_answers:\n  [interpreted_angle, studentAnswer[1], studentAnswer[2], studentAnswer[3]]\n\ngap_feedback (Feedback on each of the gaps):\n    map(\n        try(\n            let(\n                result, submit_part(gaps[gap_number][\"path\"],answer),\n                gap, gaps[gap_number],\n                name, gap[\"name\"],  \n                noFeedbackIcon, not gap[\"settings\"][\"showFeedbackIcon\"],\n                assert(name=\"\" or len(gaps)=1,feedback(translate('part.gapfill.feedback header',[\"name\": name])));\n                concat_feedback(filter(x[\"op\"]<>\"warning\",x,result[\"feedback\"]), if(marks>0,result[\"marks\"]/marks,1), noFeedbackIcon);\n                    result\n            ),\n            err,\n            fail(translate(\"part.gapfill.error marking gap\",[\"name\": gaps[gap_number][\"name\"], \"message\": err]))\n        ),\n        [gap_number,answer,index],\n        zip([3,0],[studentAnswer[3], interpreted_angle],[1,2])\n    )\n\n", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Determine the magnitude and direction of the reaction at pin $A$.</p>\n<p>Force $\\mathbf{A}$ has a magnitude of [[3]]&nbsp;</p>\n<p>acting at an angle of&nbsp;[[0]] measured&nbsp;[[1]]&nbsp;from the [[2]].</p>\n<p><span data-jme-visible=\"debug\"><strong>A</strong>&nbsp;= {magA}, angle={dirA}&deg;</span></p>", "gaps": [{"type": "angle", "useCustomName": true, "customName": "angleA", "marks": "10", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "settings": {"expected_answer": "qty(dirA,'deg')", "unit_penalty": "20", "close_penalty": "20", "close_tol": "0.5", "right_tol": "0.2"}}, {"type": "1_n_2", "useCustomName": true, "customName": "sign", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "dropdownlist", "displayColumns": 0, "showCellAnswerState": true, "choices": ["CCW", "CW"], "matrix": [0, 0], "distractors": ["", ""]}, {"type": "1_n_2", "useCustomName": true, "customName": "ref", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "dropdownlist", "displayColumns": 0, "showCellAnswerState": true, "choices": ["+x axis", "+y axis", "-x axis", "-y axis"], "matrix": [0, 0, 0, 0], "distractors": ["", "", "", ""]}, {"type": "engineering-answer", "useCustomName": true, "customName": "magA", "marks": "10", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "settings": {"correctAnswer": "magA", "right": "0.2", "close": "1.0", "C1": "75", "C2": "50", "C3": "25"}}], "sortAnswers": false}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "contributors": [{"name": "William Haynes", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2530/"}]}]}], "contributors": [{"name": "William Haynes", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2530/"}]}