m = 68.1

m =

   68.1000

g = 9.81

g =

    9.8100

c = 0.25

c =

    0.2500

skydiver_error(m,g,c)

  dt      vtrue    vapprox       et        ea
2.00	  49.42	    51.31	  3.826	      NaN
1.00	  49.42	    50.43	  2.038	    1.752
0.50	  49.42	    49.93	  1.036	    0.992
0.25	  49.42	    49.68	  0.521	    0.512

skydiver_error2(m,g,c)

npts =

     2


npts =

     2


npts =

     2


npts =

     2


  dt      vtrue    vapprox       et        ea
2.00	  18.73	    19.62	  4.756	      NaN
1.00	   9.69	     9.81	  1.198	    100.000
0.50	   4.89	     4.91	  0.300	    100.000
0.25	   2.45	     2.45	  0.075	    100.000

uiopen('F:\EGM4344\Lecture 12\Working\skydiver_func1.m', true);
t = 4;
v = skydiver_func1(m,g,c,t)

v =

   33.1118

v = skydiver_func1(70,g,c,t)

v =

   33.2478

v = skydiver_func1(100,g,c,t)

v =

   34.8026

v = skydiver_func1(120,g,c,t)

v =

   35.4569

v = skydiver_func1(140,g,c,t)

v =

   35.9430

v = skydiver_func1(150,g,c,t)

v =

   36.1420

v = skydiver_func1(145,g,c,t)

v =

   36.0456

edit
skydiver_graphical
uiopen('F:\EGM4344\Lecture 12\Working\bisection.m', true);
func = 'skydiver_zero'

func =

skydiver_zero

xb = [75 150];
tol = 0.1

tol =

    0.1000

verbose = true;
r = bisection(func,xb,tol,verbose)

Bisection iterations for skydiver_zero.m

  k       fm            xm            ea
  1  -7.6451e-001   1.1250e+002   1.3233e+004
  2  -2.5337e-001   1.3125e+002   1.4286e+001
  3  -4.3800e-002   1.4063e+002   6.6667e+000
  4   5.1828e-002   1.4531e+002   3.2258e+000
  5   4.7208e-003   1.4297e+002   1.6393e+000
  6  -1.9359e-002   1.4180e+002   8.2645e-001
  7  -7.2744e-003   1.4238e+002   4.1152e-001
  8  -1.2657e-003   1.4268e+002   2.0534e-001
  9   1.7303e-003   1.4282e+002   1.0256e-001
 10   2.3298e-004   1.4275e+002   5.1308e-002

r =

  142.7490


diary off