// Numbas version: finer_feedback_settings {"name": "Maria's copy of Rate of change", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"rulesets": {}, "variables": {"b": {"name": "b", "description": "", "templateType": "randrange", "group": "Ungrouped variables", "definition": "random(3..10#1)"}, "a": {"name": "a", "description": "", "templateType": "randrange", "group": "Ungrouped variables", "definition": "random(100..300#5)"}}, "name": "Maria's copy of Rate of change", "variablesTest": {"maxRuns": 100, "condition": ""}, "functions": {}, "ungrouped_variables": ["a", "b"], "tags": [], "metadata": {"description": "
Rate of change problem involving velocity & acceleration
", "licence": "Creative Commons Attribution 4.0 International"}, "extensions": [], "parts": [{"type": "gapfill", "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "marks": 0, "gaps": [{"minValue": "{a}-9.8*{b}", "allowFractions": false, "precisionPartialCredit": 0, "marks": 1, "scripts": {}, "strictPrecision": false, "precisionMessage": "You have not given your answer to the correct precision.", "type": "numberentry", "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "precisionType": "dp", "showPrecisionHint": false, "maxValue": "{a}-9.8*{b}", "correctAnswerFraction": false, "variableReplacements": [], "precision": "1"}, {"minValue": "{a}^2/19.6", "allowFractions": false, "precisionPartialCredit": 0, "marks": 1, "scripts": {}, "strictPrecision": false, "precisionMessage": "You have not given your answer to the correct precision.", "type": "numberentry", "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "precisionType": "dp", "showPrecisionHint": false, "maxValue": "{a}^2/19.6", "correctAnswerFraction": false, "variableReplacements": [], "precision": "1"}], "scripts": {}, "variableReplacements": [], "prompt": "Calculate the speed of the missile (m/s) \\(\\var{b}\\) seconds after launch. Give your answer correct to one decimal place.
\n\\(v = \\) [[0]]m/s
\nWhat is the maximum height achieved by this missile? Give your answer correct to one decimal place.
\n\\(h = \\) [[1]]m
"}], "advice": "\\(h=\\var{a}t-4.9t^2\\)
\nRecall that speed is the rate of change of position with respect to time i.e. \\(v=\\frac{dh}{dt}\\)
\n\\(v=\\frac{dh}{dt}=\\var{a}-2*4.9t\\)
\nwhen \\(t=\\var{b}\\)
\n\\(v=\\var{a}-2*4.9*\\var{b}\\)
\n\\(v=\\simplify{{a}-9.8*{b}}m/s\\)
\n\nThe missile will reach its maximum height when its speed = 0. i.e. \\(v=\\frac{dh}{dt}=\\var{a}-2*4.9t=0\\)
\n\\(\\var{a}=9.8t\\)
\n\\(t=\\var{a}/9.8\\)
\nThe maximum height reached will occur when \\(t=\\simplify{{a}/9.8}\\)
\n\\(h=\\var{a}*\\left(\\simplify{{a}/9.8}\\right)-4.9*\\left(\\simplify{{a}/9.8}\\right)^2\\)
\n\\(h=\\simplify{{a}^2/19.6}\\)
\n\\(h=\\simplify{{{a}/{19.6}^0.5}^2}\\)
\n\n", "variable_groups": [], "statement": "A missile is launched straight up in the air. The height of the missile, \\(h\\) metres, above the ground \\(t\\) seconds after the launch button is pressed is given by:
\n\\(h=\\var{a}t-4.9t^2\\)
", "preamble": {"css": "", "js": ""}, "type": "question", "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}, {"name": "Maria Aneiros", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3388/"}]}]}], "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}, {"name": "Maria Aneiros", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3388/"}]}