Correct answer
Student view placeholder
In student views this area is used for assessment and score info.
Tools
Staff information
Question
Title:
Demo: Drawing of FBD and obtaining reactions (with force pair)
Variant
Started at:
2026-08-04 22:49:11 (CDT)
Duration:
0s
Show/Hide answer
{
"box": [
{
"id": 0,
"x1": 80,
"x2": 180,
"x3": 340,
"y1": 280,
"y2": 100,
"y3": 100,
"type": "pl-3pointrod",
"color": "#ffffff",
"graded": false,
"height": 20,
"label1": "A",
"label2": "B",
"label3": "C",
"stroke": "#000000",
"drawPin": true,
"evented": false,
"offsetx1": 20,
"offsetx2": 0,
"offsetx3": 0,
"offsety1": -20,
"offsety2": 10,
"offsety3": 10,
"selectable": false,
"gradingName": "pl-3pointrod",
"strokeWidth": 2
},
{
"id": 1,
"top": 100,
"fill": "#000000",
"left": 340,
"type": "pl-arc-dimensions",
"angle": 0,
"label": "\\\\theta",
"graded": false,
"radius": 60,
"stroke": "#000000",
"evented": false,
"offsetx": 10,
"offsety": 0,
"originY": "center",
"endAngle": 0,
"selectable": false,
"startAngle": -30,
"gradingName": "pl-arc-dimensions",
"strokeWidth": 1,
"drawEndArrow": true,
"drawStartArrow": true,
"endSupportLine": true,
"drawCenterPoint": false,
"startSupportLine": true,
"arrowheadWidthRatio": 1,
"arrowheadOffsetRatio": 1
},
{
"id": 2,
"top": 280,
"fill": "#808080",
"left": 340,
"type": "pl-circle",
"label": "",
"graded": false,
"radius": 60,
"stroke": "#000000",
"evented": false,
"offsetx": 5,
"offsety": 5,
"opacity": 1,
"originX": "center",
"originY": "center",
"scaling": true,
"selectable": false,
"gradingName": "pl-circle",
"strokeWidth": 1,
"strokeUniform": true
},
{
"id": 3,
"top": 280,
"fill": "#000000",
"left": 340,
"type": "pl-point",
"label": "C",
"graded": false,
"radius": 4,
"evented": false,
"offsetx": 5,
"offsety": 5,
"opacity": 1,
"originX": "center",
"originY": "center",
"selectable": false,
"gradingName": "pl-point",
"widthErrorBox": 20,
"heightErrorBox": 20,
"XcenterErrorBox": 340,
"YcenterErrorBox": 280,
"objectDrawErrorBox": null
},
{
"id": 4,
"top": 331.9615242270663,
"fill": "#000000",
"left": 370,
"type": "pl-point",
"label": "",
"graded": false,
"radius": 4,
"evented": false,
"offsetx": 5,
"offsety": 5,
"opacity": 1,
"originX": "center",
"originY": "center",
"selectable": false,
"gradingName": "pl-point",
"widthErrorBox": 20,
"heightErrorBox": 20,
"XcenterErrorBox": 370,
"YcenterErrorBox": 331.9615242270663,
"objectDrawErrorBox": null
},
{
"id": 5,
"x1": 180,
"y1": 100,
"top": 40,
"left": 180,
"type": "pl-vector",
"angle": 90,
"label": "",
"width": 60,
"graded": true,
"stroke": "#c72c1c",
"evented": false,
"offsetx": 2,
"offsety": 2,
"originY": "center",
"selectable": false,
"gradingName": "pl-vector",
"strokeWidth": 3,
"trueHandles": [
"mtr"
],
"drawEndArrow": true,
"drawErrorBox": true,
"widthErrorBox": 80,
"drawStartArrow": false,
"heightErrorBox": 20,
"offset_forward": 0,
"XcenterErrorBox": 180,
"YcenterErrorBox": 70,
"disregard_sense": false,
"offset_backward": 60,
"optional_grading": false,
"objectDrawErrorBox": null,
"arrowheadWidthRatio": 1,
"arrowheadOffsetRatio": 1
},
{
"id": 6,
"x1": 80,
"y1": 280,
"top": 280,
"left": 80,
"type": "pl-vector",
"angle": 0,
"label": "",
"width": 60,
"graded": true,
"stroke": "#c72c1c",
"evented": false,
"offsetx": 2,
"offsety": 2,
"originY": "center",
"selectable": false,
"gradingName": "pl-vector",
"strokeWidth": 3,
"trueHandles": [
"mtr"
],
"drawEndArrow": true,
"drawErrorBox": true,
"widthErrorBox": 140,
"drawStartArrow": false,
"heightErrorBox": 20,
"offset_forward": 60,
"XcenterErrorBox": 80,
"YcenterErrorBox": 280,
"disregard_sense": true,
"offset_backward": 60,
"optional_grading": false,
"objectDrawErrorBox": null,
"arrowheadWidthRatio": 1,
"arrowheadOffsetRatio": 1
},
{
"id": 7,
"x1": 80,
"y1": 280,
"top": 280,
"left": 80,
"type": "pl-vector",
"angle": -90,
"label": "",
"width": 60,
"graded": true,
"stroke": "#c72c1c",
"evented": false,
"offsetx": 2,
"offsety": 2,
"originY": "center",
"selectable": false,
"gradingName": "pl-vector",
"strokeWidth": 3,
"trueHandles": [
"mtr"
],
"drawEndArrow": true,
"drawErrorBox": true,
"widthErrorBox": 140,
"drawStartArrow": false,
"heightErrorBox": 20,
"offset_forward": 60,
"XcenterErrorBox": 80,
"YcenterErrorBox": 280,
"disregard_sense": true,
"offset_backward": 60,
"optional_grading": false,
"objectDrawErrorBox": null,
"arrowheadWidthRatio": 1,
"arrowheadOffsetRatio": 1
},
{
"id": 8,
"x1": 370,
"y1": 331.9615242270663,
"top": 383.92304845413264,
"left": 400,
"type": "pl-vector",
"angle": -120,
"label": "",
"width": 60,
"graded": true,
"stroke": "#c72c1c",
"evented": false,
"offsetx": 2,
"offsety": 2,
"originY": "center",
"selectable": false,
"gradingName": "pl-vector",
"strokeWidth": 3,
"trueHandles": [
"mtr"
],
"drawEndArrow": true,
"drawErrorBox": true,
"widthErrorBox": 140,
"drawStartArrow": false,
"heightErrorBox": 20,
"offset_forward": 60,
"XcenterErrorBox": 370,
"YcenterErrorBox": 331.9615242270663,
"disregard_sense": true,
"offset_backward": 60,
"optional_grading": false,
"objectDrawErrorBox": null,
"arrowheadWidthRatio": 1,
"arrowheadOffsetRatio": 1
},
{
"id": 9,
"x1": 340,
"x2": 340,
"y1": 100,
"y2": 280,
"top1": 100,
"top2": 280,
"type": "pl-paired-vector",
"label": "",
"left1": 340,
"left2": 340,
"width": 60,
"angle1": -120,
"angle2": 60,
"graded": true,
"stroke": "#c72c1c",
"evented": false,
"offsetx": 2,
"offsety": 2,
"originY": "center",
"selectable": false,
"gradingName": "pl-paired-vector",
"strokeWidth": 3,
"trueHandles": [
"mtr"
],
"drawEndArrow": true,
"drawErrorBox": true,
"drawStartArrow": false,
"offset_forward": 60,
"widthErrorBox1": 140,
"widthErrorBox2": 140,
"disregard_sense": true,
"heightErrorBox1": 20,
"heightErrorBox2": 20,
"offset_backward": 60,
"XcenterErrorBox1": 340,
"XcenterErrorBox2": 340,
"YcenterErrorBox1": 100,
"YcenterErrorBox2": 280,
"optional_grading": false,
"objectDrawErrorBox": null,
"arrowheadWidthRatio": 1,
"arrowheadOffsetRatio": 1
}
]
}