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{"name": "Weir equation lab", "extensions": [], "custom_part_types": [], "resources": [["question-resources/weir1.PNG", "/srv/numbas/media/question-resources/weir1.PNG"], ["question-resources/weir1_MKuZ09J.PNG", "/srv/numbas/media/question-resources/weir1_MKuZ09J.PNG"], ["question-resources/weir2.PNG", "/srv/numbas/media/question-resources/weir2.PNG"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Weir equation lab", "tags": [], "metadata": {"description": "Fourth fluid mechanics lab.&nbsp;", "licence": "All rights reserved"}, "statement": "<p>Answer this question using your laboratory measurements and the Excel calculations and analysis template corresponding to the rectangular and V-notch Weir lab. You're expected to have completed all calculations and plots before attempting this question.&nbsp;</p>", "advice": "<p>For a rectangular weir we know that for a given notch width b (m), a water height above the notch H (m), and discharge Q (m<sup>3</sup>s<sup>-1</sup>), the discharge coefficient is given by:&nbsp;</p>\n<p><img src=\"resources/question-resources/weir1.PNG\" width=\"152\" height=\"68\"/>&nbsp;</p>\n<p>Therefore, c<sub>d</sub> =&nbsp;(3*{Q})/(2*0.03*((2*9.81)^0.5)*{H}^1.5) = {Cd}</p>\n<p></p>\n<p>For a triangular weir we know that for a given notch&nbsp;angle&nbsp;theta (radians), a water height above the notch H (m), and discharge Q (m<sup>3</sup>s<sup>-1</sup>), the discharge coefficient is given by:&nbsp;</p>\n<p><img src=\"resources/question-resources/weir2.PNG\" width=\"156\" height=\"67\"/></p>\n<p>Therefore, c<sub>d</sub>&nbsp;= (15*{Qt)/(8*TAN(90*((3.14/180/2))*SQRT(2*9.81)*Ht^2.5)) = {Cdt}</p>\n<p></p>\n<p></p>", "rulesets": {}, "extensions": [], "variables": {"H": {"name": "H", "group": "Rectangular weir", "definition": "0.084", "description": "<p>Height above notch (m)</p>", "templateType": "anything"}, "Q": {"name": "Q", "group": "Rectangular weir", "definition": "0.0013 ", "description": "<p>Discharge (cumecs)</p>", "templateType": "anything"}, "Cd": {"name": "Cd", "group": "Rectangular weir", "definition": "(3*Q)/(2*0.03*((2*9.81)^0.5)*H^1.5)", "description": "<p>Rectangular coefficient of discharge</p>", "templateType": "anything"}, "Ht": {"name": "Ht", "group": "Triangular weir", "definition": "0.083", "description": "<p>Water height above notch (m)</p>", "templateType": "anything"}, "Qt": {"name": "Qt", "group": "Triangular weir", "definition": "0.0015", "description": "<p>Discharge (cumecs)</p>", "templateType": "anything"}, "Cdt": {"name": "Cdt", "group": "Triangular weir", "definition": "(15*Qt)/(8*TAN(90*((3.14/180/2))*SQRT(2*9.81)*Ht^2.5))", "description": "<p>Triangular weir coefficient of discharge</p>", "templateType": "anything"}, "flow": {"name": "flow", "group": "Rectangular weir", "definition": "random(1,2,3,4,5,6,7,8)", "description": "", "templateType": "anything"}, "flowv": {"name": "flowv", "group": "Triangular weir", "definition": "random(1,2,3,4,5,6,7,8)", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": [], "variable_groups": [{"name": "Rectangular weir", "variables": ["H", "Q", "Cd", "flow"]}, {"name": "Triangular weir", "variables": ["Ht", "Qt", "Cdt", "flowv"]}], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "gapfill", "useCustomName": false, "customName": "", "marks": 0, "showCorrectAnswer": true, "showFeedbackIcon": true, "scripts": {}, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "adaptiveMarkingPenalty": 0, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "prompt": "<p>For the rectangular weir, under flow condition {flow}:</p>\n<p>Enter the&nbsp;water height above the notch base, H (m): [[0]]</p>\n<p>Enter the discharge flowing over the weir, Q (m<sup>3</sup>s<sup>-1</sup>): [[1]]</p>\n<p>Enter the corresponding discharge coefficient C<sub>d</sub>: [[2]]</p>", "gaps": [{"type": "numberentry", "useCustomName": false, "customName": "", "marks": "0", "showCorrectAnswer": true, "showFeedbackIcon": true, "scripts": {}, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "adaptiveMarkingPenalty": 0, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "minValue": "0", "maxValue": "0.12", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": false, "customName": "", "marks": "0", "showCorrectAnswer": true, "showFeedbackIcon": true, "scripts": {}, 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"mustBeReducedPC": 0, "precisionType": "dp", "precision": "3", "precisionPartialCredit": 0, "precisionMessage": "You have not given your answer to the correct precision.", "strictPrecision": true, "showPrecisionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}, {"type": "gapfill", "useCustomName": false, "customName": "", "marks": 0, "showCorrectAnswer": true, "showFeedbackIcon": true, "scripts": {}, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "adaptiveMarkingPenalty": 0, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "prompt": "<p>For the triangular weir, under flow condition {flowv}:</p>\n<p>Enter the&nbsp;water height above the notch base, H (m): [[0]]</p>\n<p>Enter the discharge flowing over the weir, Q (m<sup>3</sup>s<sup>-1</sup>): [[1]]</p>\n<p>Enter the corresponding discharge coefficient C<sub>d</sub>: [[2]]</p>", "gaps": [{"type": "numberentry", 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