// Numbas version: finer_feedback_settings
{"name": "Bonus Assignment", "metadata": {"description": "<p><strong>MECE3930U: Heat Transfer Bonus Assignment (Transient Heat Conduction).</strong></p>\n<p><em>Please follow the Numbas guidance first if you did not attend the Numbas&nbsp;session.</em></p>", "licence": "None specified"}, "duration": 0, "percentPass": 0, "showQuestionGroupNames": false, "shuffleQuestionGroups": false, "showstudentname": true, "question_groups": [{"name": "Group", "pickingStrategy": "all-ordered", "pickQuestions": 1, "questionNames": [""], "variable_overrides": [[]], "questions": [{"name": "Bonus Problem - Transient Heat Conduction", "extensions": [], "custom_part_types": [{"source": {"pk": 7, "author": {"name": "Christian Lawson-Perfect", "pk": 7}, "edit_page": "/part_type/7/edit"}, "name": "Quantity with units", "short_name": "quantity", "description": "<p>The student enters a quantity with units.</p>", "help_url": "https://github.com/numbas/numbas-extension-quantities", "input_widget": "string", "input_options": {"correctAnswer": "plain_string(settings[\"correctAnswer\"])", "hint": {"static": false, "value": "switch(\n  settings[\"hint\"]=\"remind units\",\n    \"Include units in your answer.\",\n  settings[\"hint\"]=\"show units\",\n    \"Give your answer in \"+units_string(settings[\"correctAnswer\"])\n  ,\n    \"\"\n)"}, "allowEmpty": {"static": true, "value": false}}, "can_be_gap": true, "can_be_step": true, "marking_script": "mark:\napply(valid_number);\napply(student_quantity);\napply(has_units);\napply(compatible);\ntry(\n  correctif(close_enough),\n  x,\n  apply(student_quantity)\n);\napply(same_units)\n\ninterpreted_answer:\nstudent_quantity\n\nallowed_notation_styles:\n[\"plain\",\"en\"]\n\nmatch_student_number:\nmatchnumber(studentAnswer,allowed_notation_styles)\n\nstudent_number:\nmatch_student_number[1]\n\nraw_student_units:\ntry(\n  quantity(studentAnswer[len(match_student_number[0])..len(studentAnswer)]),\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)\n\nstudent_units:\nif(compatible(raw_student_units,correct_units) or settings[\"incompatible_units_action\"]<>\"convert\",\n  raw_student_units,\n  correct_units\n)\n\nstudent_quantity:\napply(student_units);\ntry(\n  student_number * student_units,\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)\n\ncorrect_quantity:\nsettings[\"correctAnswer\"]\n\ncompatible:\nif(compatible(raw_student_units,correct_quantity),\n  true\n,\n  let(message,\"Your answer does not have the correct dimensions.\",\n    if(settings[\"incompatible_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n      if(settings[\"incompatible_units_action\"]=\"convert\",\n        incorrect(\"Your answer does not have the correct dimensions. It will be marked as if the correct dimensions were used, and then a penalty will be applied.\")\n        ,\n        incorrect(\"Your answer does not have the correct dimensions.\");\n        end()\n      )\n    );\n    false\n  )\n)\n\ncorrect_units:\nunits(correct_quantity)\n\nsame_units:\nassert(raw_student_units=correct_units,\n  let(\n    message,if(settings[\"hint\"]=\"show units\",\"You did not give your answer in \"+units_string(correct_units)+\".\", \"Your answer is not in the expected units.\"),\n  switch(\n    settings[\"different_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n    settings[\"different_units_action\"]=\"incorrect\",\n      incorrect(message); \n      warn(message);\n      end()\n    ,\n    settings[\"different_units_action\"]=\"warn\",\n      warn(message);\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n    settings[\"different_units_penalty\"]<1,\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n      false\n  )\n  );\n  false\n)\n\nhas_units:\nassert(not unitless(student_quantity),\n  assert(settings[\"allow_unitless\"],\n    warn(\"You must include the units in your answer.\");\n    fail(\"You did not include units in your answer.\")\n  )\n)\n\ncan_compare:\ncompatible or settings[\"incompatible_units_action\"]=\"convert\"\n\nclose_enough:\nif(can_compare,\n   student_quantity>=correct_quantity - wiggle \n   and \n   student_quantity<=correct_quantity + wiggle \n,\n   false\n)\n\nwiggle:\nunits(correct_quantity)*abs(eval(settings[\"wiggle\"]))\n\nvalid_number:\nif(isNaN(student_number),\n   warn(translate(\"part.numberentry.answer invalid\"));\n   fail(translate(\"part.numberentry.answer invalid\"))\n,\n  true\n  )", "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": "apply(valid_number);\napply(student_quantity);\napply(has_units);\napply(compatible);\ntry(\n  correctif(close_enough),\n  x,\n  apply(student_quantity)\n);\napply(same_units)"}, {"name": "interpreted_answer", "description": "A value representing the student's answer to this part.", "definition": "student_quantity"}, {"name": "allowed_notation_styles", "description": "", "definition": "[\"plain\",\"en\"]"}, {"name": "match_student_number", "description": "", "definition": "matchnumber(studentAnswer,allowed_notation_styles)"}, {"name": "student_number", "description": "<p>The scalar part of the student's quantity</p>", "definition": "match_student_number[1]"}, {"name": "raw_student_units", "description": "<p>The units of the student's quantity, before converting.</p>", "definition": "try(\n  quantity(studentAnswer[len(match_student_number[0])..len(studentAnswer)]),\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)"}, {"name": "student_units", "description": "<p>The units of the student's quantity.</p>\n<p>If the student used units incompatible with the units in the expected answer, and the \"what to do if incompatible units used\" option is set to \"mark as if correct units used\", the student's units are ignored and the expected units are used instead.</p>", "definition": "if(compatible(raw_student_units,correct_units) or settings[\"incompatible_units_action\"]<>\"convert\",\n  raw_student_units,\n  correct_units\n)"}, {"name": "student_quantity", "description": "<p>The student's answer, interpreted as a quantity.</p>\n<p>Marking fails if the student does not enter a valid quantity.</p>", "definition": "apply(student_units);\ntry(\n  student_number * student_units,\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)"}, {"name": "correct_quantity", "description": "", "definition": "settings[\"correctAnswer\"]"}, {"name": "compatible", "description": "<p>Are the units of the student's quantity compatible with the units of the expected quantity?</p>", "definition": "if(compatible(raw_student_units,correct_quantity),\n  true\n,\n  let(message,\"Your answer does not have the correct dimensions.\",\n    if(settings[\"incompatible_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n      if(settings[\"incompatible_units_action\"]=\"convert\",\n        incorrect(\"Your answer does not have the correct dimensions. It will be marked as if the correct dimensions were used, and then a penalty will be applied.\")\n        ,\n        incorrect(\"Your answer does not have the correct dimensions.\");\n        end()\n      )\n    );\n    false\n  )\n)"}, {"name": "correct_units", "description": "", "definition": "units(correct_quantity)"}, {"name": "same_units", "description": "<p>/Are the student's quantity and the expected quantity in exactly the same units?</p>", "definition": "assert(raw_student_units=correct_units,\n  let(\n    message,if(settings[\"hint\"]=\"show units\",\"You did not give your answer in \"+units_string(correct_units)+\".\", \"Your answer is not in the expected units.\"),\n  switch(\n    settings[\"different_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n    settings[\"different_units_action\"]=\"incorrect\",\n      incorrect(message); \n      warn(message);\n      end()\n    ,\n    settings[\"different_units_action\"]=\"warn\",\n      warn(message);\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n    settings[\"different_units_penalty\"]<1,\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n      false\n  )\n  );\n  false\n)"}, {"name": "has_units", "description": "", "definition": "assert(not unitless(student_quantity),\n  assert(settings[\"allow_unitless\"],\n    warn(\"You must include the units in your answer.\");\n    fail(\"You did not include units in your answer.\")\n  )\n)"}, {"name": "can_compare", "description": "<p>Can the student's answer be compared with the correct answer? True if compatible units used, or \"mark as if correct units used\" selected.</p>", "definition": "compatible or settings[\"incompatible_units_action\"]=\"convert\""}, {"name": "close_enough", "description": "<p>Is the student's quantity within the allowed tolerance of the expected answer?</p>", "definition": "if(can_compare,\n   student_quantity>=correct_quantity - wiggle \n   and \n   student_quantity<=correct_quantity + wiggle \n,\n   false\n)"}, {"name": "wiggle", "description": "", "definition": "units(correct_quantity)*abs(eval(settings[\"wiggle\"]))"}, {"name": "valid_number", "description": "<p>Is the scalar part of the student's answer a valid number?</p>", "definition": "if(isNaN(student_number),\n   warn(translate(\"part.numberentry.answer invalid\"));\n   fail(translate(\"part.numberentry.answer invalid\"))\n,\n  true\n  )\n"}], "settings": [{"name": "correctAnswer", "label": "Correct answer", "help_url": "", "hint": "The expected quantity.", "input_type": "code", "default_value": "", "evaluate": true}, {"name": "hint", "label": "Input hint", "help_url": "", "hint": "", "input_type": "dropdown", "default_value": "remind units", "choices": [{"value": "none", "label": "None"}, {"value": "remind units", "label": "Remind to include units"}, {"value": "show units", "label": "Show required units"}]}, {"name": "allow_unitless", "label": "Allow unitless answer?", "help_url": "", "hint": "If not ticked, the student is prevented from submitting an answer without specifying units.", "input_type": "checkbox", "default_value": true}, {"name": "incompatible_units_action", "label": "What to do if incompatible units used", "help_url": "", "hint": "If the student's answer is given in units incompatible with the correct answer's units:<br />\n<ul>\n<li>\"Prevent submission\": Prevent the student from submitting until they use compatible units</li>\n<li>\"Mark as incorrect\": Mark the student's answer as incorrect.</li>\n<li>\"Mark as if correct units used\": Mark the student's answer as if they used the correct units, and apply the \"different units used\" penalty.</li>\n</ul>", "input_type": "dropdown", "default_value": "incorrect", "choices": [{"value": "incorrect", "label": "Mark as incorrect"}, {"value": "prevent", "label": "Prevent submission"}, {"value": "convert", "label": "Mark as if correct units used"}]}, {"name": "different_units_action", "label": "What to do if different units used", "help_url": "", "hint": "If the student's answer is given in different units to the expected answer:<br />\n<ul>\n<li>\"Convert\" - silently convert the student's answer to the units used in the correct answer.</li>\n<li>\"Warn and convert\" - show a warning to the student, but convert.</li>\n<li>\"Prevent submission\" - don't allow the student to submit, and show a warning that they must use the same units.</li>\n<li>\"Mark incorrect\" - the student's answer is marked as incorrect.</li>\n</ul>", "input_type": "dropdown", "default_value": "convert", "choices": [{"value": "convert", "label": "Convert"}, {"value": "warn", "label": "Warn and convert"}, {"value": "prevent", "label": "Prevent submission"}, {"value": "incorrect", "label": "Mark incorrect"}]}, {"name": "different_units_penalty", "label": "Penalty if different units used", "help_url": "", "hint": "This penalty is applied if the student gives their answer in different units to the expected answer. The selected percentage of the student's score is taken away.", "input_type": "percent", "default_value": "100"}, {"name": "wiggle", "label": "Margin of error", "help_url": "", "hint": "The student's answer is marked correct if the difference between it and the correct answer is at most this value, measured in the same units as the correct answer.", "input_type": "mathematical_expression", "default_value": "10^-12", "subvars": true}], "public_availability": "always", "published": true, "extensions": ["quantities"]}], "resources": ["question-resources/brass_cylinder.png"], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Seama Koohi", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/4775/"}], "tags": [], "metadata": {"description": "", "licence": "None specified"}, "statement": "<p>A brass cylinder of diameter <strong>$\\var{D}$ mm</strong> and height <strong>$\\var{H}$ mm</strong>&nbsp;&nbsp;is initially at a uniform temperature of <strong>$\\var{Ti}$ &deg;C</strong>. The cylinder is suddenly exposed to atmospheric air at <strong>20&deg;C</strong>, where heat is transferred by convection with a heat transfer coefficient of <strong>h = 40 W/m&sup2;&middot;K</strong>.</p>\n<p>The thermophysical properties of brass are density of <strong>8530 kg/m3</strong>, specific heat capacity of <strong>0.389 kJ/kg.&deg;C</strong> and and thermal conductivity of <strong>110 W/m.&deg;C</strong> and all assumed to be constant during the cooling process.</p>\n<p><img src=\"resources/question-resources/brass_cylinder.png\" style=\"display: block; margin-left: auto; margin-right: auto;\"/></p>\n<p></p>", "advice": "", "rulesets": {}, "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true, "j": false}, "constants": [], "variables": {"D": {"name": "D", "group": "Ungrouped variables", "definition": "random(5 .. 15#1)", "description": "", "templateType": "randrange", "can_override": false}, "Ti": {"name": "Ti", "group": "Ungrouped variables", "definition": "random(148 .. 160#1)", "description": "", "templateType": "randrange", "can_override": false}, "H": {"name": "H", "group": "Ungrouped variables", "definition": "random(10 .. 25#1)", "description": "", "templateType": "randrange", "can_override": false}, "hc": {"name": "hc", "group": "Ungrouped variables", "definition": "40", "description": "", "templateType": "number", "can_override": false}, "k": {"name": "k", "group": "Ungrouped variables", "definition": "110", "description": "", "templateType": "number", "can_override": false}, "Bi": {"name": "Bi", "group": "Ungrouped variables", "definition": "hc*lc/k", "description": "", "templateType": "anything", "can_override": false}, "t": {"name": "t", "group": "Ungrouped variables", "definition": "900", "description": "", "templateType": "number", "can_override": false}, "Ro": {"name": "Ro", "group": "Ungrouped variables", "definition": "8530", "description": "", "templateType": "number", "can_override": false}, "Cp": {"name": "Cp", "group": "Ungrouped variables", "definition": "389", "description": "", "templateType": "number", "can_override": false}, "Tinf": {"name": "Tinf", "group": "Ungrouped variables", "definition": "20", "description": "", "templateType": "number", "can_override": false}, "Tf": {"name": "Tf", "group": "Ungrouped variables", "definition": "Tinf+((Ti-Tinf)*exp(-b*t))", "description": "", "templateType": "anything", "can_override": false}, "Q": {"name": "Q", "group": "Ungrouped variables", "definition": "-Ro*(pi*d0^2*h0/4)*Cp*(Tf-Ti)", "description": "", "templateType": "anything", "can_override": false}, "d0": {"name": "d0", "group": "Ungrouped variables", "definition": "0.001*d", "description": "", "templateType": "anything", "can_override": false}, "h0": {"name": "h0", "group": "Ungrouped variables", "definition": "0.001*h", "description": "", "templateType": "anything", "can_override": false}, "b": {"name": "b", "group": "Ungrouped variables", "definition": "hc/(Ro*Cp*lc)", "description": "", "templateType": "anything", "can_override": false}, "Lc": {"name": "Lc", "group": "Ungrouped variables", "definition": "(d0*h0)/((4*h0)+(2*d0))", "description": "", "templateType": "anything", "can_override": false}, "Kmax": {"name": "Kmax", "group": "Ungrouped variables", "definition": "10*hc*lc", "description": "", "templateType": "anything", "can_override": false}, "Dmax": {"name": "Dmax", "group": "Ungrouped variables", "definition": "1000*(0.4*kmax*h0)/((hc*h0)-(0.2*kmax))", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["D", "Ti", "H", "hc", "k", "Bi", "t", "Ro", "Cp", "d0", "h0", "b", "Tinf", "Tf", "Q", "Lc", "Kmax", "Dmax"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "1_n_2", "useCustomName": true, "customName": "Part a)", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Without doing any calculations, what are possibly the independent variables that are present in the temperature function for this problem?</p>", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showBlankOption": true, "showCellAnswerState": true, "choices": ["Time", "Space-related variables", "Time and space-related variables"], "matrix": [0, 0, "0.8"], "distractors": ["", "", ""]}, {"type": "1_n_2", "useCustomName": true, "customName": "Part b)", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p dir=\"auto\">Following the previous question, what dimensionless number assists in deciding what independent variables are present?</p>", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showBlankOption": true, "showCellAnswerState": true, "choices": ["Nusselt", "Biot", "Reynolds"], "matrix": [0, "0.8", 0], "distractors": ["", "", ""]}, {"type": "1_n_2", "useCustomName": true, "customName": "Part c)", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>What characteristic length would you use for calculation of this dimensionless number?</p>", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showBlankOption": true, "showCellAnswerState": true, "choices": ["Cylinder diameter", "Cylinder radius", "Cylinder volume / surface area&nbsp;"], "matrix": [0, 0, "0.8"], "distractors": ["", "", ""]}, {"type": "numberentry", "useCustomName": true, "customName": "Part d)", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>What is the value for the dimensionless number that you selected?</p>", "minValue": "0.7*Bi", "maxValue": "1.3*Bi", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "precisionType": "dp", "precision": "4", "precisionPartialCredit": 0, "precisionMessage": "You have not given your answer to the correct precision.", "strictPrecision": false, "showPrecisionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "1_n_2", "useCustomName": true, "customName": "Part e)", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Now, with the new knowledge of Bio, which model is appropriate for describing the temperature inside the cylinder during cooling ?<br/><br/>Hint: compare&nbsp;Biot number.</p>", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showBlankOption": true, "showCellAnswerState": true, "choices": ["a)&nbsp;Lumped-capacitance model&nbsp;(temperature can be assumed uniform)", "Transient conduction with spatial temperature gradients"], "matrix": ["0.8", 0], "distractors": ["", ""]}, {"type": "quantity", "useCustomName": true, "customName": "Part f)", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Determine the temperature of the cylinder at its center after <strong>15</strong> minutes. Please use celsius&nbsp;as the unit of your answer.</p>", "settings": {"correctAnswer": "qty(Tf,\"celsius\")", "hint": "show units", "allow_unitless": true, "incompatible_units_action": "prevent", "different_units_action": "prevent", "different_units_penalty": "0", "wiggle": "1"}}, {"type": "quantity", "useCustomName": true, "customName": "Part g)", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Determine the temperature of the cylinder at its surface after 15 minutes. Please use celsius as the unit of your answer.</p>", "settings": {"correctAnswer": "qty(Tf,\"celsius\")", "hint": "show units", "allow_unitless": true, "incompatible_units_action": "prevent", "different_units_action": "prevent", "different_units_penalty": "0", "wiggle": "1"}}, {"type": "quantity", "useCustomName": true, "customName": "Part h)", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Determine the&nbsp;total amount of heat transferred&nbsp;from the cylinder to the air during this time? Give your answer in&nbsp;J</p>", "settings": {"correctAnswer": "qty(Q,\"J\")", "hint": "show units", "allow_unitless": true, "incompatible_units_action": "prevent", "different_units_action": "prevent", "different_units_penalty": "0", "wiggle": "1"}}, {"type": "1_n_2", "useCustomName": true, "customName": "Part i)", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p dir=\"auto\">If the convection coefficient h is doubled, how does the cooling time change to reach the same final temperature (using the lumped model). Assume all other parameters are fixed.&nbsp; &nbsp; <em><strong>Hint:</strong> From the lumped-capacitance relation, see how t scales with h.</em></p>\n<div dir=\"auto\"></div>\n<div dir=\"auto\"></div>\n<div dir=\"auto\"></div>\n<div dir=\"auto\"></div>", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showBlankOption": true, "showCellAnswerState": true, "choices": ["Decrease by a factor of 2", "Decrease but not necessarily by exactly 2", "Increase", "Stay the same"], "matrix": ["0.8", 0, 0, 0], "distractors": ["", "", "", ""]}, {"type": "quantity", "useCustomName": true, "customName": "Part j)", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Below what material thermal conductivity would have resulted the above solution method to become invalid? Please use W/mC as the unit of your answer.</p>", "settings": {"correctAnswer": "qty(kmax,\"W/mC\")", "hint": "show units", "allow_unitless": true, "incompatible_units_action": "prevent", "different_units_action": "prevent", "different_units_penalty": "0", "wiggle": "0.05"}}, {"type": "quantity", "useCustomName": true, "customName": "Part k)", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Following the previous question and assuming this thermal conductivity for the solid, a cylinder of at least what diameter would have resulted the above solution to become valid again? Provide your answer in mm.</p>", "settings": {"correctAnswer": "qty(dmax,\"mm\")", "hint": "show units", "allow_unitless": true, "incompatible_units_action": "prevent", "different_units_action": "prevent", "different_units_penalty": "0", "wiggle": "0.5"}}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always"}]}], "allowPrinting": true, "navigation": {"allowregen": true, "reverse": true, "browse": true, "allowsteps": true, "showfrontpage": true, "navigatemode": "sequence", "onleave": {"action": "warnifunattempted", "message": "<p>You did not complete all the questions. Are you sure you want to leave?</p>"}, "preventleave": true, "typeendtoleave": false, "startpassword": "", "autoSubmit": true, "allowAttemptDownload": true, "downloadEncryptionKey": "", "showresultspage": "oncompletion"}, "timing": {"allowPause": true, "timeout": {"action": "none", "message": ""}, "timedwarning": {"action": "none", "message": ""}}, "feedback": {"enterreviewmodeimmediately": true, "showactualmarkwhen": "always", "showtotalmarkwhen": "always", "showanswerstatewhen": "always", "showpartfeedbackmessageswhen": "always", "showexpectedanswerswhen": "inreview", "showadvicewhen": "inreview", "allowrevealanswer": true, "intro": "<p>If you get a full grade, do not use assignment link to Numbas to start a new exam or it will overwrite your previous grade.</p>", "end_message": "", "results_options": {"printquestions": true, "printadvice": true}, "feedbackmessages": [], "reviewshowexpectedanswer": true, "showanswerstate": true, "reviewshowfeedback": true, "showactualmark": true, "showtotalmark": true, "reviewshowscore": true, "reviewshowadvice": true}, "diagnostic": {"knowledge_graph": {"topics": [], "learning_objectives": []}, "script": "diagnosys", "customScript": ""}, "contributors": [{"name": "Seama Koohi", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/4775/"}], "extensions": ["quantities"], "custom_part_types": [{"source": {"pk": 7, "author": {"name": "Christian Lawson-Perfect", "pk": 7}, "edit_page": "/part_type/7/edit"}, "name": "Quantity with units", "short_name": "quantity", "description": "<p>The student enters a quantity with units.</p>", "help_url": "https://github.com/numbas/numbas-extension-quantities", "input_widget": "string", "input_options": {"correctAnswer": "plain_string(settings[\"correctAnswer\"])", "hint": {"static": false, "value": "switch(\n  settings[\"hint\"]=\"remind units\",\n    \"Include units in your answer.\",\n  settings[\"hint\"]=\"show units\",\n    \"Give your answer in \"+units_string(settings[\"correctAnswer\"])\n  ,\n    \"\"\n)"}, "allowEmpty": {"static": true, "value": false}}, "can_be_gap": true, "can_be_step": true, "marking_script": "mark:\napply(valid_number);\napply(student_quantity);\napply(has_units);\napply(compatible);\ntry(\n  correctif(close_enough),\n  x,\n  apply(student_quantity)\n);\napply(same_units)\n\ninterpreted_answer:\nstudent_quantity\n\nallowed_notation_styles:\n[\"plain\",\"en\"]\n\nmatch_student_number:\nmatchnumber(studentAnswer,allowed_notation_styles)\n\nstudent_number:\nmatch_student_number[1]\n\nraw_student_units:\ntry(\n  quantity(studentAnswer[len(match_student_number[0])..len(studentAnswer)]),\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)\n\nstudent_units:\nif(compatible(raw_student_units,correct_units) or settings[\"incompatible_units_action\"]<>\"convert\",\n  raw_student_units,\n  correct_units\n)\n\nstudent_quantity:\napply(student_units);\ntry(\n  student_number * student_units,\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)\n\ncorrect_quantity:\nsettings[\"correctAnswer\"]\n\ncompatible:\nif(compatible(raw_student_units,correct_quantity),\n  true\n,\n  let(message,\"Your answer does not have the correct dimensions.\",\n    if(settings[\"incompatible_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n      if(settings[\"incompatible_units_action\"]=\"convert\",\n        incorrect(\"Your answer does not have the correct dimensions. It will be marked as if the correct dimensions were used, and then a penalty will be applied.\")\n        ,\n        incorrect(\"Your answer does not have the correct dimensions.\");\n        end()\n      )\n    );\n    false\n  )\n)\n\ncorrect_units:\nunits(correct_quantity)\n\nsame_units:\nassert(raw_student_units=correct_units,\n  let(\n    message,if(settings[\"hint\"]=\"show units\",\"You did not give your answer in \"+units_string(correct_units)+\".\", \"Your answer is not in the expected units.\"),\n  switch(\n    settings[\"different_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n    settings[\"different_units_action\"]=\"incorrect\",\n      incorrect(message); \n      warn(message);\n      end()\n    ,\n    settings[\"different_units_action\"]=\"warn\",\n      warn(message);\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n    settings[\"different_units_penalty\"]<1,\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n      false\n  )\n  );\n  false\n)\n\nhas_units:\nassert(not unitless(student_quantity),\n  assert(settings[\"allow_unitless\"],\n    warn(\"You must include the units in your answer.\");\n    fail(\"You did not include units in your answer.\")\n  )\n)\n\ncan_compare:\ncompatible or settings[\"incompatible_units_action\"]=\"convert\"\n\nclose_enough:\nif(can_compare,\n   student_quantity>=correct_quantity - wiggle \n   and \n   student_quantity<=correct_quantity + wiggle \n,\n   false\n)\n\nwiggle:\nunits(correct_quantity)*abs(eval(settings[\"wiggle\"]))\n\nvalid_number:\nif(isNaN(student_number),\n   warn(translate(\"part.numberentry.answer invalid\"));\n   fail(translate(\"part.numberentry.answer invalid\"))\n,\n  true\n  )", "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": "apply(valid_number);\napply(student_quantity);\napply(has_units);\napply(compatible);\ntry(\n  correctif(close_enough),\n  x,\n  apply(student_quantity)\n);\napply(same_units)"}, {"name": "interpreted_answer", "description": "A value representing the student's answer to this part.", "definition": "student_quantity"}, {"name": "allowed_notation_styles", "description": "", "definition": "[\"plain\",\"en\"]"}, {"name": "match_student_number", "description": "", "definition": "matchnumber(studentAnswer,allowed_notation_styles)"}, {"name": "student_number", "description": "<p>The scalar part of the student's quantity</p>", "definition": "match_student_number[1]"}, {"name": "raw_student_units", "description": "<p>The units of the student's quantity, before converting.</p>", "definition": "try(\n  quantity(studentAnswer[len(match_student_number[0])..len(studentAnswer)]),\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)"}, {"name": "student_units", "description": "<p>The units of the student's quantity.</p>\n<p>If the student used units incompatible with the units in the expected answer, and the \"what to do if incompatible units used\" option is set to \"mark as if correct units used\", the student's units are ignored and the expected units are used instead.</p>", "definition": "if(compatible(raw_student_units,correct_units) or settings[\"incompatible_units_action\"]<>\"convert\",\n  raw_student_units,\n  correct_units\n)"}, {"name": "student_quantity", "description": "<p>The student's answer, interpreted as a quantity.</p>\n<p>Marking fails if the student does not enter a valid quantity.</p>", "definition": "apply(student_units);\ntry(\n  student_number * student_units,\n  message,\n  warn(\"Your answer is not a valid quantity.\");\n  fail(\"Your answer is not a valid quantity.\")\n)"}, {"name": "correct_quantity", "description": "", "definition": "settings[\"correctAnswer\"]"}, {"name": "compatible", "description": "<p>Are the units of the student's quantity compatible with the units of the expected quantity?</p>", "definition": "if(compatible(raw_student_units,correct_quantity),\n  true\n,\n  let(message,\"Your answer does not have the correct dimensions.\",\n    if(settings[\"incompatible_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n      if(settings[\"incompatible_units_action\"]=\"convert\",\n        incorrect(\"Your answer does not have the correct dimensions. It will be marked as if the correct dimensions were used, and then a penalty will be applied.\")\n        ,\n        incorrect(\"Your answer does not have the correct dimensions.\");\n        end()\n      )\n    );\n    false\n  )\n)"}, {"name": "correct_units", "description": "", "definition": "units(correct_quantity)"}, {"name": "same_units", "description": "<p>/Are the student's quantity and the expected quantity in exactly the same units?</p>", "definition": "assert(raw_student_units=correct_units,\n  let(\n    message,if(settings[\"hint\"]=\"show units\",\"You did not give your answer in \"+units_string(correct_units)+\".\", \"Your answer is not in the expected units.\"),\n  switch(\n    settings[\"different_units_action\"]=\"prevent\",\n      warn(message);\n      fail(message)\n    ,\n    settings[\"different_units_action\"]=\"incorrect\",\n      incorrect(message); \n      warn(message);\n      end()\n    ,\n    settings[\"different_units_action\"]=\"warn\",\n      warn(message);\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n    settings[\"different_units_penalty\"]<1,\n      multiply_credit(1-settings[\"different_units_penalty\"],message)\n    ,\n      false\n  )\n  );\n  false\n)"}, {"name": "has_units", "description": "", "definition": "assert(not unitless(student_quantity),\n  assert(settings[\"allow_unitless\"],\n    warn(\"You must include the units in your answer.\");\n    fail(\"You did not include units in your answer.\")\n  )\n)"}, {"name": "can_compare", "description": "<p>Can the student's answer be compared with the correct answer? True if compatible units used, or \"mark as if correct units used\" selected.</p>", "definition": "compatible or settings[\"incompatible_units_action\"]=\"convert\""}, {"name": "close_enough", "description": "<p>Is the student's quantity within the allowed tolerance of the expected answer?</p>", "definition": "if(can_compare,\n   student_quantity>=correct_quantity - wiggle \n   and \n   student_quantity<=correct_quantity + wiggle \n,\n   false\n)"}, {"name": "wiggle", "description": "", "definition": "units(correct_quantity)*abs(eval(settings[\"wiggle\"]))"}, {"name": "valid_number", "description": "<p>Is the scalar part of the student's answer a valid number?</p>", "definition": "if(isNaN(student_number),\n   warn(translate(\"part.numberentry.answer invalid\"));\n   fail(translate(\"part.numberentry.answer invalid\"))\n,\n  true\n  )\n"}], "settings": [{"name": "correctAnswer", "label": "Correct answer", "help_url": "", "hint": "The expected quantity.", "input_type": "code", "default_value": "", "evaluate": true}, {"name": "hint", "label": "Input hint", "help_url": "", "hint": "", "input_type": "dropdown", "default_value": "remind units", "choices": [{"value": "none", "label": "None"}, {"value": "remind units", "label": "Remind to include units"}, {"value": "show units", "label": "Show required units"}]}, {"name": "allow_unitless", "label": "Allow unitless answer?", "help_url": "", "hint": "If not ticked, the student is prevented from submitting an answer without specifying units.", "input_type": "checkbox", "default_value": true}, {"name": "incompatible_units_action", "label": "What to do if incompatible units used", "help_url": "", "hint": "If the student's answer is given in units incompatible with the correct answer's units:<br />\n<ul>\n<li>\"Prevent submission\": Prevent the student from submitting until they use compatible units</li>\n<li>\"Mark as incorrect\": Mark the student's answer as incorrect.</li>\n<li>\"Mark as if correct units used\": Mark the student's answer as if they used the correct units, and apply the \"different units used\" penalty.</li>\n</ul>", "input_type": "dropdown", "default_value": "incorrect", "choices": [{"value": "incorrect", "label": "Mark as incorrect"}, {"value": "prevent", "label": "Prevent submission"}, {"value": "convert", "label": "Mark as if correct units used"}]}, {"name": "different_units_action", "label": "What to do if different units used", "help_url": "", "hint": "If the student's answer is given in different units to the expected answer:<br />\n<ul>\n<li>\"Convert\" - silently convert the student's answer to the units used in the correct answer.</li>\n<li>\"Warn and convert\" - show a warning to the student, but convert.</li>\n<li>\"Prevent submission\" - don't allow the student to submit, and show a warning that they must use the same units.</li>\n<li>\"Mark incorrect\" - the student's answer is marked as incorrect.</li>\n</ul>", "input_type": "dropdown", "default_value": "convert", "choices": [{"value": "convert", "label": "Convert"}, {"value": "warn", "label": "Warn and convert"}, {"value": "prevent", "label": "Prevent submission"}, {"value": "incorrect", "label": "Mark incorrect"}]}, {"name": "different_units_penalty", "label": "Penalty if different units used", "help_url": "", "hint": "This penalty is applied if the student gives their answer in different units to the expected answer. The selected percentage of the student's score is taken away.", "input_type": "percent", "default_value": "100"}, {"name": "wiggle", "label": "Margin of error", "help_url": "", "hint": "The student's answer is marked correct if the difference between it and the correct answer is at most this value, measured in the same units as the correct answer.", "input_type": "mathematical_expression", "default_value": "10^-12", "subvars": true}], "public_availability": "always", "published": true, "extensions": ["quantities"]}], "resources": [["question-resources/brass_cylinder.png", "/srv/numbas/media/question-resources/brass_cylinder.png"]]}