HP 15c - Manual (Page 14)

14 The HP-15C: A Problem Solver
The time an object takes to fall to the ground (ignoring air friction) is given
by the formula
g
2h
t

,
where t = time in seconds,
h = height in meters,
g = the acceleration due to gravity,
9.8 m/s
2
.
Example: Compute the time taken by a
stone falling from the top of the Eiffel
Tower (300.51 meters high) to the earth.
Keystrokes Display
300.51
v 300.5100
Enter h.
2
* 601.0200
Calculates 2h.
9.8
÷ 61.3286
(2h) /g.
¤ 7.8313
Falling time, seconds.
Programmed Solutions
Suppose you wanted to calculate falling times from various heights. The
easiest way is to write a program to cover all the constant parts of a
calculation and provide for entry of variable data.
Writing the Program. The program is similar to the keystroke sequence
you used above. A label is useful to define the beginning of a program, and
a return is useful to mark the end of a program. Also, the program must
accommodate the entry of new data.
Loading the Program. You can load a program for the above problem by
pressing the following keys in sequence. (The display shows information
which you can ignore for now, though it will be useful later.)