HP 48G - Andthe MES

Of course, you can also use the MES on your own
groups of equations—just put your desired equations
into a list. And you can use the built-in group of pro-
jectile motion equations as the starting point.
Example: Suppose you want to know the trajectory
angle(s), 6,, needed for a target at range 6000 m, ele-
vation 1200 m, with a 300 m/s muzzle velocity. You
can’t do this easily with just the built-in equations list,
but you can add the necessary equation to a copy of
that list, then store this as, say, PR:
Highlight Frojectile Mot ion in the Equa-
tion Library (as in the previous example), but then just
press to send that group’s equation list to the
stack. Now just key in the necessary new equation:
"BA=ATANC (y—gB ) Cu—wB)+C0ONST (9) 2
#( (=l ) (UB 2=C0SCAAIMEY D)
this onto the stack and press (+]to add it to the
list already there. Name this, (' Ja]«]PJR]0] JJENTER]
(STO), and it's ready to use in the MES—via (G]EQ LB):
(113)
GRENECLIE
EcHLIzOLVE[MsOL] | [EGLIE]
(115) ({3
coWLifcoNs] | [ [EGLIE]
QRY HE:
II I N T
(117) (S
MINE [ZFACT|FRNNI[DARCY] Fik [SIDEN
T T (T T I T
] JEGLEE
Press I E)Q)@]STO), to denote your
list as the current equation set. Now press
=3 initialize (EILTH), and startthe MES (IEEIM).
If you use the data above, you'll get a trajectory angle
of about 34.07° or 67.23°, depending on your initial
guess for B8 (don’t forget about multiple solutions—
guessing works just as in the regular Solver).*
See the Command Index (pages 41-77) for details on
the other items in LB—more MES commands,
the Constants Library, the MMINEHUNT game, etc.
*Note, too, that the presence of units in your own MES equation lists is
not automatic. As in the regular Solver, if the variables do not already
exist, they will be created by the MES without associated units; you
must then key in the desired units with your initial input values.
and the MES 37