HP 50G, User Manual

Page: 254 / 887

Page 7-17
Adding an INFO button to your directory
An information button can be useful for your directory to help you remember the
operation of the functions in the directory. In this directory, all we need to
remember is to press
@TRISO
to get a triangle solution started. You may want to
type in the following program:
<<“Press [TRISO] to start.“ MSGBOX >>,
and store it
in a variable called INFO. As a result, the first variable in your directory will be
the
@INFO
button
.
Application 2 - Velocity and acceleration in polar coordinates
Two-dimensional particle motion in polar coordinates often involves determining
the radial and transverse components of the velocity and acceleration of the
particle given r, r’ = dr/dt, r” = d
2
r/dt
2
,
θ
,
θ
’ = d
θ
/dt, and,
θ
” = d
2
θ
/dt
2
.
The following equations are used:
Create a subdirectory called POLC (POLar Coordinates), which we will use to
calculate velocities and accelerations in polar coordinates. Within that
subdirectory, enter the following variables:
a
b c α(
ο
) β(
ο
) γ(
ο
) A
2.5 6.9837 7.2 20.229 75 84.771 8.6933
7.2 8.5 14.26 22.616 27 130.38 23.309
21.92 17.5 13.2 90 52.98 37.03 115.5
41.92 23 29.6 75 32 73 328.81
10.27 3.26 10.5 77 18 85 16.66
17 25 32 31.79 50.78 97.44 210.71
Program or value Store into variable:
<< PEQ STEQ MINIT NAME LIST MITM MSOLVR >>
"vel. & acc. polar coord."
{ r rD rDD
θ
D
θ
DD vr v
θ
v ar a
θ
a }
{ 'vr = rD' 'v
θ
= r*
θ
D' 'v =
√
(vr^2 + v
θ
^2)'
'ar = rDD
−
r*
θ
D^2' 'a
θ
= r*
θ
DD + 2*rD*
θ
D'
'a =
√
(ar^2 + a
θ
^2)' }
SOLVEP
NAME
LIST
PEQ
θ θ θ
θ
θ θ
&
&
&& &
&
&& &
r r a r v
r r a r v
r r
2
2
+ = =
− = =