I enjoyed the lesson very much but wondered what he's actually calculating.

**increment = 1**

t = 0.00 s = 0.00 phi = 0.00

t = 1.00 s = 101.29 phi = -9.15

t = 2.00 s = 212.34 phi = -25.78

t = 3.00 s = 340.72 phi = -38.83

t = 4.00 s = 491.39 phi = -48.42

t = 5.00 s = 667.44 phi = -55.39

t = 6.00 s = 870.83 phi = -60.55

t = 7.00 s = 1102.79 phi = -64.46
s = 1102.79

=======

**increment = 0.5**

t = 0.00 s = 0.00 phi = 0.00

t = 0.50 s = 50.16 phi = -4.60

t = 1.00 s = 101.60 phi = -13.58

t = 1.50 s = 155.50 phi = -21.92

t = 2.00 s = 212.89 phi = -29.40

t = 2.50 s = 274.63 phi = -35.92

t = 3.00 s = 341.42 phi = -41.52

t = 3.50 s = 413.79 phi = -46.30

t = 4.00 s = 492.18 phi = -50.37

t = 4.50 s = 576.93 phi = -53.84

t = 5.00 s = 668.30 phi = -56.82

t = 5.50 s = 766.50 phi = -59.39

t = 6.00 s = 871.72 phi = -61.63

t = 6.50 s = 984.08 phi = -63.58

t = 7.00 s = 1103.71 phi = -65.29
s = 1103.71

=======

Here's the Python-program that does it:

#!/usr/bin/python
from math import sqrt, atan2, pi

def deg(rad):

return 180*rad/pi

v = 100

g = 32.2

(x0, y0) = (x, y) = (0, 800)

s = 0

t = 7

inc = 0.5

for n in range(0, int(round(t/inc)) + 1):

t = inc * n

(x_, y_) = (x, y)

(x, y) = (x0 + v*t, y0 - g*t**2/2)

(dx, dy) = (x - x_, y - y_)

ds = sqrt(dx**2 + dy**2)

s += ds

phi = deg(atan2(dy, dx))

print "t = %6.2f s = %8.2f phi = %8.2f" % (t, s, phi)

print

print "s = %8.2f" % s

Quote:

And what would happen if we put in a hundredth?

s = 1104.01

=======

Can somebody provide an actual program for the HP-9100?

Kind regards

Thomas

PS: Just noticed that the time in the video doesn't seem to be correct: it's always one step ahead.

*Edited: 6 Dec 2012, 8:36 p.m. *