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  "signature": "sha256:5a553b2a442e6221dea12996ec8dc7d308a698d61fa5538169e60bbcf11198bb"
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 4 : Equilibrium"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.3 Page No : 71"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "from numpy import linalg\t\t\n",
      "        \t\n",
      "# Variables\n",
      "W = 100. \t\t\t#lb\n",
      "a1 = 30. \t\t\t#degrees\n",
      "a2 = 45. \t\t\t#degrees\n",
      "\t\t\t\n",
      "# Calculations\n",
      "A =[[math.cos(math.radians(a2)),-math.cos(math.radians(a1))],[math.sin(math.radians(a2)),math.sin(math.radians(a1))]]\n",
      "b =[[0],[W]]\n",
      "c = linalg.solve(A,b)\n",
      "Tbc = c[0]\n",
      "Tab = c[1]\n",
      "\t\t\t\n",
      "# Results\n",
      "print  'Tbc = %.1f lb'%(Tbc)\n",
      "print  'Tab =%.1f lb'%(Tab)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Tbc = 89.7 lb\n",
        "Tab =73.2 lb\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.4 Page No : 72"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\t\t\t\n",
      "# Variables\n",
      "W1 = 7000. \t\t\t#lb\n",
      "W2 = 1000. \t\t\t#lb\n",
      "W3 = 3000. \t\t\t#lb\n",
      "x1 = 6. \t\t\t#in\n",
      "x2 = 9. \t\t\t#in\n",
      "x3 = 10. \t\t\t#in\n",
      "x4 = 5. \t\t\t#in\n",
      "\t\t\t\n",
      "# Calculations\n",
      "Rb = (W1*x1+W2*(x1+x2)+W3*(x1+x2+x3))/(x1+x2+x3+x4)\n",
      "Ra = W1+W2+W3-Rb\n",
      "\t\t\t\n",
      "# Results\n",
      "print  'Rb = %.1f lb'%(Rb)\n",
      "print  'Ra = %.1f lb'%(Ra)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Rb = 4400.0 lb\n",
        "Ra = 6600.0 lb\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.5 Page No : 74"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\t\t\t\n",
      "# Variables\n",
      "Fc = 500. \t\t\t#lb\n",
      "Fd = 1000. \t\t\t#lb\n",
      "xc = 2. \t\t\t#in\n",
      "xd = 8. \t\t\t#in\n",
      "y = 6.   \t\t\t#in\n",
      "\t\t\t\n",
      "# Calculations\n",
      "Ay = Fc+Fd\n",
      "Bx = (Fc*xc+Fd*xd)/y\n",
      "Ax = Bx\n",
      "A = math.sqrt(Ax**2+Ay**2)\n",
      "\t\t\t\n",
      "# Results\n",
      "print  'A = %.f lb'%(A)\n",
      "print  'B = %.f lb'%(Bx)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "A = 2121 lb\n",
        "B = 1500 lb\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.6 Page No : 75"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\t\t\t\n",
      "# Variables\n",
      "W = -300. \t\t\t#lb\n",
      "r = 4. \t\t\t#in\n",
      "x1 = 2. \t\t\t#ft\n",
      "x2 = 3. \t\t\t#ft\n",
      "x3 = 1. \t\t\t#ft\n",
      "y1 = 1. \t\t\t#ft\n",
      "x4 = 3. \t\t\t#in\n",
      "\t\t\t\n",
      "# Calculations\n",
      "F = -W*r/(y1*12)\n",
      "By = -W*x1/(x1+x2)\n",
      "Bz = -F*(x1+x2+x3+(x4/12))/(x1+x2)\n",
      "Ay = -W-By\n",
      "Az = -F-Bz\n",
      "\t\t\t\n",
      "# Results\n",
      "print  'Ay  = %.2f lb'%(Ay)\n",
      "print  'By = %.2f lb'%(By)\n",
      "print  'Az = %.2f lb'%(Az)\n",
      "print  'Bz = %.2f lb'%(Bz)\n",
      "print  'F = %.2f lb'%(F)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Ay  = 180.00 lb\n",
        "By = 120.00 lb\n",
        "Az = 25.00 lb\n",
        "Bz = -125.00 lb\n",
        "F = 100.00 lb\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.7 Page No : 77"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math \n",
      "\t\t\t\n",
      "# Variables\n",
      "W = 500. \t\t\t#lb\n",
      "r = 4. \t\t\t#in\n",
      "Lx = 3. \t\t\t#in\n",
      "Ly = 12. \t\t\t#in\n",
      "Lz = 4. \t\t\t#in\n",
      "\t\t\t\n",
      "# Calculations\n",
      "Tbd = W*(math.sqrt((-Lx)**2+(-Ly)**2+(-Lz)**2))/Ly\n",
      "Tcd = Lx*Tbd/(math.sqrt((-Lx)**2+(-Ly)**2+(-Lz)**2))\n",
      "Tad = Lz*Tbd/(math.sqrt((-Lx)**2+(-Ly)**2+(-Lz)**2))\n",
      "\t\t\t\n",
      "# Results\n",
      "print  'Tbd = %.f lb'%(Tbd)\n",
      "print  'Tcd =%.f lb'%(Tcd)\n",
      "print  'Tad =%.f lb'%(Tad)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Tbd = 542 lb\n",
        "Tcd =125 lb\n",
        "Tad =167 lb\n"
       ]
      }
     ],
     "prompt_number": 5
    }
   ],
   "metadata": {}
  }
 ]
}