// Numbas version: exam_results_page_options
{"name": "Q4", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Q4", "tags": [], "metadata": {"description": "", "licence": "None specified"}, "statement": "", "advice": "", "rulesets": {}, "extensions": [], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true}, "constants": [], "variables": {"period": {"name": "period", "group": "Ungrouped variables", "definition": "random(1.4 .. 1.9#0.1)", "description": "", "templateType": "randrange", "can_override": false}, "frequency": {"name": "frequency", "group": "Ungrouped variables", "definition": "1/(period/1000)", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["period", "frequency"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "gapfill", "useCustomName": true, "customName": "a", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>If the period of a sound is {period} x 10${^3}$, what is the frequency?</p>\n<p>ans = [[0]] Hz</p>", "gaps": [{"type": "numberentry", "useCustomName": false, "customName": "", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "{frequency}*0.9", "maxValue": "{frequency}*1.1", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}, {"type": "1_n_2", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>The formula for calculating the observed frequency of a wave altered by the Doppler effect is:</p>\n<p><em> $f_o \\frac{v\\frac{+}{-} v_o}{v \\frac{+}{-}v_s}$</em></p>\n<p><em>where ${f_o}$ is the observed frequency,v is the velocity of sound,&nbsp; ${v_o}$ is the velocity of the observer and ${v_s}$ is the velocity of the source.</em></p>\n<p><em>If the source and the observer are both moving in the same direction, which of the following statements is true?</em></p>", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showCellAnswerState": true, "choices": ["<em>${v_o}$ and ${v_s}$ are both positive</em>", "<em>${v_o}$ and ${v_s}$ are both negative</em>", "<em>${v_o}$ is negative and ${v_s}$ is positive</em>", "<em>${v_s}$ is negative and ${v_o}$ is positive</em>"], "matrix": [0, "1", 0, 0], "distractors": ["", "", "", ""]}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "contributors": [{"name": "Stephen Sheridan", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/10056/"}]}]}], "contributors": [{"name": "Stephen Sheridan", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/10056/"}]}