{"job_id":"anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482","request_id":"bulk-2026-05-21T09-46-48-791Z-3-a1-physics.08.friction.static-to-kinetic","status":"complete","asset":{"primary_url":"https://storage.googleapis.com/pupiltree-animation-assets/anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482/walkthrough.mp4","thumbnail_url":"https://storage.googleapis.com/pupiltree-animation-assets/anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482/thumb.jpg","transcript_url":"https://storage.googleapis.com/pupiltree-animation-assets/anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482/transcript.vtt","interactive_url":"https://storage.googleapis.com/pupiltree-animation-assets/anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482/index.html","scenefile_url":"https://storage.googleapis.com/pupiltree-animation-assets/anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482/scene-source.json","duration_seconds":15,"byte_size":469586,"renderer":"html_three_js_local","parameters":{"style":"auto","executor":"native_render_executor","localPath":"/app/storage/assets/anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482","interactivity":"none","renderer_style":"three_js","durationSeconds":15,"render_manifest":{"jobId":"anim-job-6d5f7a18-dd0c-40a8-822b-1c28477f7482","request":{"gap":{"topic":"friction-static_to_kinetic","severity":"moderate","error_type":"concept_misunderstanding","memory_state":"fragile","display_topic":"Static to Kinetic Friction","common_wrong_answer":"The concept works the same way in all conditions.","confidence_at_error":"high","correct_understanding":"The concept depends on constraints, assumptions, and variable relationships."},"target":{"style":"auto","render":{"fps":30,"format":"mp4","resolution":"1920x1080","include_thumbnail":true,"include_transcript":true},"audience":{"tone":"neutral_instructional","grade":"8","language":"en"},"interactivity":"none","duration_seconds":15},"context":{"chapter":{"name":"Friction","ncert_class":8},"sub_topics":[{"topic":"friction-static_to_kinetic","key_concepts":["Static to Kinetic Friction","Friction"]}]},"metadata":{"priority":"normal","trace_id":"bulk-run-2026-05-21T09-46-48-791Z"},"exam_type":"neet","asset_type":"simulation","request_id":"bulk-2026-05-21T09-46-48-791Z-3-a1-physics.08.friction.static-to-kinetic","subject_area":"physics"},"renderer":"html_three_js_local","storyboard":{"beats":[{"label":"Topic","visual":"Show the topic title and the key physical context.","narration":"Static to Kinetic Friction"},{"label":"Mistake","visual":"Show the wrong approach and why it seems plausible.","narration":"The concept works the same way in all conditions."},{"label":"Correction","visual":"Show the right approach step by step.","narration":"The concept depends on constraints, assumptions, and variable relationships."},{"label":"Concept","visual":"Highlight the key formula and the governing relationship.","narration":"Static to Kinetic Friction. Friction"}],"title":"Static to Kinetic Friction","sceneCode":"<!doctype html>\n<html lang=\"en\">\n<head>\n  <meta charset=\"utf-8\"/>\n  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\"/>\n  <title>Static vs Kinetic Friction: Condition-Dependent Behavior</title>\n  <style>\n    :root{--bg:#eef2f5;--panel:#ffffff;--line:#cfd8e3;--accent:#3b82f6;--text:#2f3b4a;--muted:#6b7a90;--blue:#3b82f6;--green:#159947;--red:#e76f51;}\n    *{box-sizing:border-box;}\n    body{margin:0;font-family:\"Plus Jakarta Sans\",\"Manrope\",\"Inter\",ui-sans-serif,system-ui,sans-serif;background:var(--bg);color:var(--text);}\n    main{min-height:100vh;display:grid;grid-template-columns:minmax(300px,380px) 1fr;}\n    aside{border-right:1px solid var(--line);background:var(--panel);padding:24px;overflow:auto;}\n    section{padding:24px;display:grid;place-items:center;}\n    h1{margin:0 0 10px;font-size:1.65rem;line-height:1.15;}\n    .sub{margin:0 0 16px;color:var(--muted);}\n    .formula{margin:0 0 14px;padding:10px;border:1px solid var(--line);border-radius:10px;background:#f7f9fc;color:#243447;font-family:ui-monospace,monospace;font-size:0.9rem;line-height:1.4;}\n    .control{display:grid;gap:6px;margin:12px 0;}\n    .control input{width:100%;accent-color:var(--accent);}\n    .control span{font-size:0.85rem;}\n    ul{margin:14px 0 0 18px;padding:0;color:var(--muted);display:grid;gap:8px;font-size:0.9rem;}\n    li{line-height:1.4;}\n    .stage{width:min(1020px,95%);aspect-ratio:16/9;border:1px solid var(--line);border-radius:14px;position:relative;overflow:hidden;background:#f6f8fb;box-shadow:0 6px 20px rgba(20,33,61,.08);}\n    .legend{position:absolute;right:12px;top:12px;padding:8px 10px;border-radius:10px;border:1px solid var(--line);background:#ffffff;font-size:0.8rem;color:var(--muted);}\n    @media(max-width:900px){main{grid-template-columns:1fr;}aside{border-right:0;border-bottom:1px solid var(--line);}}\n  </style>\n</head>\n<body>\n<main>\n  <aside>\n    <h1>Static vs Kinetic Friction</h1>\n    <p class=\"sub\">Why friction behaves differently before and after motion</p>\n    <p class=\"formula\">\n      f<sub>s</sub> ≤ μ<sub>s</sub>·N (not moving)<br/>\n      f<sub>k</sub> = μ<sub>k</sub>·N (moving)<br/>\n      μ<sub>s</sub> &gt; μ<sub>k</sub> always\n    </p>\n    <label class=\"control\"><span>Applied Force: <strong id=\"v-force\">20</strong> N</span><input id=\"c-force\" type=\"range\" min=\"5\" max=\"80\" step=\"5\" value=\"20\"/></label>\n    <label class=\"control\"><span>μ<sub>s</sub> (static): <strong id=\"v-mus\">0.60</strong></span><input id=\"c-mus\" type=\"range\" min=\"0.3\" max=\"1.0\" step=\"0.1\" value=\"0.60\"/></label>\n    <label class=\"control\"><span>μ<sub>k</sub> (kinetic): <strong id=\"v-muk\">0.40</strong></span><input id=\"c-muk\" type=\"range\" min=\"0.15\" max=\"0.8\" step=\"0.05\" value=\"0.40\"/></label>\n    <label class=\"control\"><span>Mass: <strong id=\"v-mass\">5.0</strong> kg</span><input id=\"c-mass\" type=\"range\" min=\"2\" max=\"15\" step=\"1\" value=\"5\"/></label>\n    <ul>\n      <li><strong style=\"color:#e76f51;\">❌ Misconception:</strong> Friction is always the same—it just equals μ·N everywhere.</li>\n      <li><strong style=\"color:#159947;\">✓ Truth:</strong> Static friction varies (up to max). Kinetic is constant. μ<sub>s</sub> &gt; μ<sub>k</sub> means harder to start moving than to keep moving.</li>\n      <li><strong style=\"color:#3b82f6;\">Key:</strong> Watch how friction changes at the moment motion begins—that's the threshold revealing two different rules.</li>\n    </ul>\n  </aside>\n  <section>\n    <div class=\"stage\" id=\"stage\">\n      <div class=\"legend\" id=\"legend\">static / kinetic threshold demo</div>\n      <canvas id=\"sim-cv\" style=\"position:absolute;inset:0;width:100%;height:100%;\"></canvas>\n    </div>\n  </section>\n</main>\n<script>\nconst controls = [\n  {\"key\":\"force\",\"label\":\"Applied Force\",\"min\":5,\"max\":80,\"step\":5,\"value\":20,\"units\":\"N\"},\n  {\"key\":\"mus\",\"label\":\"μ_s (static)\",\"min\":0.3,\"max\":1.0,\"step\":0.1,\"value\":0.60,\"units\":\"\"},\n  {\"key\":\"muk\",\"label\":\"μ_k (kinetic)\",\"min\":0.15,\"max\":0.8,\"step\":0.05,\"value\":0.40,\"units\":\"\"},\n  {\"key\":\"mass\",\"label\":\"Mass\",\"min\":2,\"max\":15,\"step\":1,\"value\":5,\"units\":\"kg\"}\n];\nfor(const c of controls){\n  const inp=document.getElementById('c-'+c.key);\n  const out=document.getElementById('v-'+c.key);\n  inp?.addEventListener('input',()=>{\n    if(c.key==='mass')out.textContent=inp.value+'.0';\n    else if(c.key==='mus'||c.key==='muk')out.textContent=inp.value;\n    else out.textContent=inp.value;\n    window.updateModel?.();\n  });\n}\n(function(){\n  const cv=document.getElementById('sim-cv');\n  const ctx=cv.getContext('2d');\n  function resize(){const r=cv.getBoundingClientRect();if(r.width>0){cv.width=r.width;cv.height=r.height;}}\n  resize();new ResizeObserver(resize).observe(cv);\n  let lastTs=0;\n  \n  // State variables\n  let posX=0;        // block position\n  let velX=0;        // block velocity\n  let isMoving=false; // are we past the static threshold?\n  let motionTime=0;  // elapsed time since motion started\n  let hasStarted=false; // has motion ever begun?\n  \n  // History for graph\n  const forceHistory=[];\n  const frictionHistory=[];\n  const timeHistory=[];\n  \n  function glowDot(x,y,r,color,a){\n    const g=ctx.createRadialGradient(x,y,0,x,y,r*2.6);\n    g.addColorStop(0,color.replace('ALPHA',String(a)));\n    g.addColorStop(1,color.replace('ALPHA','0'));\n    ctx.fillStyle=g;ctx.beginPath();ctx.arc(x,y,r*2.6,0,Math.PI*2);ctx.fill();\n  }\n  \n  function arrow(x1,y1,x2,y2,color,width){\n    const dx=x2-x1,dy=y2-y1,l=Math.sqrt(dx*dx+dy*dy);\n    if(l<3)return;\n    const nx=dx/l,ny=dy/l,s=12;\n    ctx.strokeStyle=color;ctx.lineWidth=width||2;\n    ctx.beginPath();ctx.moveTo(x1,y1);ctx.lineTo(x2,y2);ctx.stroke();\n    ctx.fillStyle=color;ctx.beginPath();\n    ctx.moveTo(x2,y2);\n    ctx.lineTo(x2-s*nx+s*0.5*ny,y2-s*ny-s*0.5*nx);\n    ctx.lineTo(x2-s*nx-s*0.5*ny,y2-s*ny+s*0.5*nx);\n    ctx.fill();\n  }\n  \n  function tick(ts){\n    const dt=Math.min(0.04,(ts-lastTs)/1000);lastTs=ts;\n    const W=cv.width,H=cv.height;\n    \n    // Read sliders\n    const F=Number(document.getElementById('c-force').value);\n    const muS=Number(document.getElementById('c-mus').value);\n    const muK=Number(document.getElementById('c-muk').value);\n    const m=Number(document.getElementById('c-mass').value);\n    \n    // Physics\n    const g=9.8;\n    const N=m*g;\n    const fMaxStatic=muS*N;\n    const fKinetic=muK*N;\n    \n    let frictionForce=0;\n    if(isMoving){\n      // Kinetic friction (constant, opposes motion)\n      frictionForce=fKinetic;\n      const netForce=F-frictionForce;\n      const accel=netForce/m;\n      velX+=accel*dt;\n      posX+=velX*dt;\n      motionTime+=dt;\n      if(velX<0)velX=0;\n      hasStarted=true;\n    }else{\n      // Static friction (adjusts to balance applied force, up to max)\n      frictionForce=Math.min(F,fMaxStatic);\n      if(F>fMaxStatic){\n        // Threshold crossed: transition to kinetic\n        isMoving=true;\n        motionTime=0;\n        velX=0;\n      }\n    }\n    \n    // Store history (trim if too long)\n    timeHistory.push(motionTime);\n    forceHistory.push(F);\n    frictionHistory.push(frictionForce);\n    if(timeHistory.length>400){\n      timeHistory.shift();forceHistory.shift();frictionHistory.shift();\n    }\n    \n    // === DRAW ===\n    ctx.clearRect(0,0,W,H);\n    \n    // Background (slightly lighter in static region)\n    ctx.fillStyle='#f6f8fb';\n    ctx.fillRect(0,0,W,H);\n    \n    // === LEFT HALF: BLOCK + FORCES ===\n    const leftW=W*0.5;\n    const blockY=H*0.55;\n    const blockH=40;\n    const blockW=50;\n    const blockX0=leftW*0.25; // origin\n    const blockActualX=blockX0+posX*30; // scale for visibility\n    \n    // Ground\n    ctx.strokeStyle='var(--line)';\n    ctx.lineWidth=2;\n    ctx.setLineDash([4,4]);\n    ctx.beginPath();ctx.moveTo(50,blockY+blockH/2+20);ctx.lineTo(leftW-20,blockY+blockH/2+20);\n    ctx.stroke();\n    ctx.setLineDash([]);\n    \n    // Block\n    ctx.fillStyle=isMoving?'#e76f51':'#3b82f6';\n    ctx.fillRect(blockActualX-blockW/2,blockY-blockH/2,blockW,blockH);\n    ctx.strokeStyle='#243447';ctx.lineWidth=1.5;\n    ctx.strokeRect(blockActualX-blockW/2,blockY-blockH/2,blockW,blockH);\n    ctx.fillStyle='#ffffff';\n    ctx.font=Math.round(H*0.04)+'px sans-serif';\n    ctx.textAlign='center';\n    ctx.fillText('m',blockActualX,blockY+4);\n    \n    // Applied force arrow (red, from left)\n    const arrowFStart=blockActualX-blockW/2-15;\n    const arrowEnd=arrowFStart-Math.max(5,F*2);\n    arrow(arrowFStart,blockY,arrowEnd,blockY,'#e76f51',3);\n    ctx.fillStyle='#e76f51';\n    ctx.font=Math.round(H*0.035)+'px sans-serif';\n    ctx.textAlign='right';\n    ctx.fillText('F='+F+'N',arrowFStart-10,blockY-20);\n    \n    // Friction force arrow (blue, to left, opposing motion)\n    const frictionArrowStart=blockActualX+blockW/2+15;\n    const frictionEnd=frictionArrowStart+Math.max(5,frictionForce*2);\n    arrow(frictionArrowStart,blockY,frictionEnd,blockY,'#3b82f6',3);\n    ctx.fillStyle='#3b82f6';\n    ctx.textAlign='left';\n    ctx.fillText('f='+Math.round(frictionForce*10)/10+'N',frictionEnd+10,blockY-20);\n    \n    // Normal force and weight (small)\n    arrow(blockActualX,blockY+blockH/2+5,blockActualX,blockY+blockH/2+40,'#6b7a90',2);\n    ctx.fillStyle='#6b7a90';\n    ctx.font=Math.round(H*0.03)+'px sans-serif';\n    ctx.textAlign='center';\n    ctx.fillText('N',blockActualX+10,blockY+blockH/2+50);\n    \n    // State label\n    ctx.fillStyle=isMoving?'#e76f51':'#159947';\n    ctx.font=Math.round(H*0.04)+'px sans-serif';\n    ctx.textAlign='center';\n    ctx.fillText(isMoving?'KINETIC FRICTION':'STATIC FRICTION',leftW/2,H*0.15);\n    \n    ctx.fillStyle='#6b7a90';\n    ctx.font=Math.round(H*0.033)+'px sans-serif';\n    ctx.fillText(isMoving?'μ_k = '+muK:'μ_s = '+muS,leftW/2,H*0.20);\n    \n    // Max static threshold indicator (only when static)\n    if(!isMoving){\n      ctx.fillStyle='rgba(231,111,81,0.15)';\n      ctx.fillRect(leftW*0.05,H*0.75,leftW*0.9,3);\n      ctx.fillStyle='#e76f51';\n      ctx.font=Math.round(H*0.03)+'px sans-serif';\n      ctx.textAlign='center';\n      ctx.fillText('Max static friction = '+Math.round(fMaxStatic*10)/10+'N (threshold)',leftW/2,H*0.82);\n    }\n    \n    // === RIGHT HALF: FRICTION vs FORCE GRAPH ===\n    const graphLeft=leftW+40;\n    const graphTop=H*0.18;\n    const graphW=W-leftW-60;\n    const graphH=H*0.65;\n    \n    // Graph background\n    ctx.fillStyle='#ffffff';\n    ctx.fillRect(graphLeft-5,graphTop-5,graphW+10,graphH+10);\n    ctx.strokeStyle='#cfd8e3","remediationGoal":"Close concept_misunderstanding for physics."},"rendererStyle":"three_js"}}},"metadata":{"rendered_at":"2026-05-21T10:02:11.367Z","cache_hit":false,"cost_usd":0},"error":null}