Motion in a Fluid
	The frictional force (drag) acting on an object moving in a fluid can be modelled using Fdrag = k v.
	In this example you may vary five factors:       initial speed (u), drag coefficient (k), gravitational field strength (g),
					mass (m), and the time (time-step) between iterations
	initial speed (m/s), u =		0.00
	drag factor, k =		0.40		acceleration due to gravity (m/s2) , g =		9.81
	time step ( / s), dt =		0.05		mass of object (/kg), m =		0.200
		t / s	v / (m/s)
		0.00	0.00
		0.05	0.49
		0.10	0.93
		0.15	1.33
		0.20	1.69
		0.25	2.01
		0.30	2.30
		0.35	2.56
		0.40	2.79
		0.45	3.01
		0.50	3.20
		0.55	3.37
		0.60	3.52
		0.65	3.66
		0.70	3.78
		0.75	3.90
		0.80	4.00
		0.85	4.09
		0.90	4.17
		0.95	4.24
		1.00	4.31
		1.05	4.37
		1.10	4.42
		1.15	4.47
		1.20	4.51
		1.25	4.55
		1.30	4.59
		1.35	4.62
		1.40	4.65
		1.45	4.67
		1.50	4.70
		1.55	4.72
		1.60	4.74
		1.65	4.75
		1.70	4.77
		1.75	4.78
		1.80	4.80
		1.85	4.81
		1.90	4.82
		1.95	4.83
		2.00	4.83
		2.05	4.84
		2.10	4.85
		2.15	4.85
		2.20	4.86
		2.25	4.86
		2.30	4.87
		2.35	4.87
		2.40	4.87
		2.45	4.88
		2.50	4.88
		2.55	4.88
		2.60	4.89
		2.65	4.89
		2.70	4.89
		2.75	4.89
		2.80	4.89
		2.85	4.89
		2.90	4.90
		2.95	4.90
		3.00	4.90