// Numbas version: finer_feedback_settings {"name": "SUVAT equations question 1", "extensions": [], "custom_part_types": [], "resources": [["question-resources/Car_image.jpg", "/srv/numbas/media/question-resources/Car_image.jpg"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {}, "ungrouped_variables": ["a", "u", "t", "v"], "name": "SUVAT equations question 1", "tags": [], "advice": "
You start by writing down the values you know and the values you need to find.
\n$a = \\var{a},$ $u=\\var{u},$ $t=\\var{t},$ $v=$ $?,$ $s=$ $?$
\na) At $B$ the car will have reached its final velocity, $v \\mathrm{ms^{-1}}$. You need $v$ and you know $u, a$ and $t$ so you can use the equation $v= u +at$. \\begin{align} v &= u + at, \\\\
&= \\var{u} + (\\var{a} \\times \\var{t}), \\\\
&= \\var{u +a*t} \\mathrm{ms^{-1}}. \\end{align}
The speed of the car at $B$ is $\\var{u + a*t} \\mathrm{ms^{-1}}.$
\nb) You need the distance, $s \\mathrm{m}$. You calculated $v$ in the previous part, so you can use the equation $s=\\left(\\frac{u+v}{2}\\right)t.$
\n\\begin{align} s &= \\left(\\frac{u+v}{2}\\right)t, \\\\
&= \\left(\\frac{\\var{u}+\\var{v}}{2}\\right) \\times \\var{t}, \\\\
&= \\var{((u+v)/2)*t} \\mathrm{m}. \\end{align}
The distance from $A$ to $B$ is $\\var{((u+v)/2)*t}$ metres.
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Find the speed of the car in $\\mathrm{ms^{-1}}$ at $B$.
", "integerAnswer": true, "allowFractions": false, "variableReplacements": [], "maxValue": "u+a*t", "minValue": "u+a*t", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 1, "type": "numberentry", "showPrecisionHint": false}, {"prompt": "Find the distance in $\\mathrm{m}$ from $A$ to $B$.
", "allowFractions": false, "variableReplacements": [], "maxValue": "(u+v)*(0.5)*t", "minValue": "(u+v)*(0.5)*t", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 1, "type": "numberentry", "showPrecisionHint": false}], "extensions": [], "statement": "\nA car is driving in a straight line from $A$ to $B$ with constant acceleration $\\var{a} \\mathrm{ms^{-2}}$.
\nIts speed at $A$ is $\\var{u} \\mathrm{ms^{-1}}$ and it takes $\\var{t}$ seconds to move from $A$ to $B$.
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"}}, "metadata": {"description": "SUVAT equation questions, for mechanics page in wiki. Uses $v=u+at$ and $s=((u+v)/2)t$.
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