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
,
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.
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.)