// Numbas version: finer_feedback_settings {"name": "Resolve force into $x$ and $y$ components", "extensions": [], "custom_part_types": [], "resources": [["question-resources/force_component_image_2.png", "/srv/numbas/media/question-resources/force_component_image_2.png"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"advice": "

a)

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We need to find the angle $\\theta_x$ of $F$ relative to the $x$-axis and then use $F \\times cos\\theta_x$.

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We consider the angle between the positive $x$-axis and $F$, i.e. $\\theta_x = 90 + \\var{theta}$.

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\\begin{align}
\\text{component in the } x \\text{-direction} & = F \\cos\\theta_x \\\\
& = \\var{force} \\times \\cos \\var{angle} \\\\
& = \\var{precround(force*cos(radians(angle)),3)}
\\end{align}

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b)

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The positive $y$-direction is vertically upwards and we need the angle relative to the positive $y$-direction therefore $\\theta_y = 180 - \\var{theta}$.

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\\begin{align}
\\text{component in the } y \\text{-direction} & = F \\cos\\theta_y \\\\
& = \\var{force} \\times \\cos \\var{yangle} \\\\
& = \\var{precround(force*cos(radians(yangle)),3)}
\\end{align}

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Notice that both these answers are negative as the force acts in the opposite direction to the positive. You could also answer these by resolving in the negative $x$ or $y$ direction and changing the sign of your solution. For example in part b) you could use $\\theta_y = \\var{theta}$ which gives $F \\cos \\theta_y = \\var{precround(-force*cos(radians(yangle)),3)}$ and then change the sign.

", "parts": [{"precision": "3", "correctAnswerFraction": false, "minValue": "force*cos(radians(angle))", "variableReplacements": [], "showCorrectAnswer": true, "prompt": "

Find the component of the force in the $x$-direction in Newtons.

", "type": "numberentry", "maxValue": "force*cos(radians(angle))", "allowFractions": false, "marks": 1, "strictPrecision": false, "precisionType": "dp", "precisionMessage": "You have not given your answer to the correct precision.", "variableReplacementStrategy": "originalfirst", "scripts": {}, "showPrecisionHint": false, "precisionPartialCredit": 0}, {"precision": "3", "correctAnswerFraction": false, "minValue": "force*cos(radians(yangle))", "variableReplacements": [], "showCorrectAnswer": true, "prompt": "

Find the component of the force in the $y$-direction in Newtons.

", "type": "numberentry", "maxValue": "force*cos(radians(yangle))", "allowFractions": false, "marks": 1, "strictPrecision": false, "precisionType": "dp", "precisionMessage": "You have not given your answer to the correct precision.", "variableReplacementStrategy": "originalfirst", "scripts": {}, "showPrecisionHint": false, "precisionPartialCredit": 0}], "variable_groups": [], "ungrouped_variables": ["force", "theta", "angle", "yangle"], "rulesets": {}, "name": "Resolve force into $x$ and $y$ components", "extensions": [], "tags": [], "type": "question", "functions": {}, "preamble": {"css": "", "js": ""}, "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "questions": [], "pickQuestions": 0}], "variablesTest": {"condition": "", "maxRuns": 100}, "metadata": {"description": "

Find the $x$ and $y$ components of a force which is applied at an angle to a particle. Resolve using $F \\cos \\theta$. The force is applied in the negative $x$ and negative $y$ direction.

", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "

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In the above diagram, $F = \\var{force} \\, \\mathrm{N}$ and $\\theta = \\var{theta}^{\\circ}$. 

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Give your answers to the following questions to 3 decimal places.

", "variables": {"force": {"templateType": "randrange", "definition": "random(3..20#0.5)", "description": "", "group": "Ungrouped variables", "name": "force"}, "theta": {"templateType": "randrange", "definition": "random(2..89#1)", "description": "", "group": "Ungrouped variables", "name": "theta"}, "angle": {"templateType": "anything", "definition": "90 + theta", "description": "", "group": "Ungrouped variables", "name": "angle"}, "yangle": {"templateType": "anything", "definition": "180-theta", "description": "", "group": "Ungrouped variables", "name": "yangle"}}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}, {"name": "Amy Chadwick", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/505/"}, {"name": "Xiaodan Leng", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2146/"}]}]}], "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}, {"name": "Amy Chadwick", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/505/"}, {"name": "Xiaodan Leng", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2146/"}]}