HP 15C: Approximate Length of Sunlight During a Day
For the HP
35S version, please click here:
Source: Total
Daily Amount of Solar Radiation  HP 67/97 Energy Conservation Pac, December
1978, Author: Hewlett Packard
Instructions:
Y
Stack: Enter the latitude (North as
positive, South as negative). Use the
D.MMSS (degreesminutesseconds) format
X
Stack: The number of days after March
21. A 365 day year is assumed, as well
as assuming March 21 is the vernal equinox.
Run the
program.
This is an
approximation.
Program:
Step

Key

Key Code

001

LBL E

42, 21, 5

002

DEG

43, 7

003

.

48

004

9

9

005

8

8

006

5

5

007

6

6

008

*

20

009

SIN

23

010

2

2

011

3

3

012

.

48

013

4

4

014

5

5

015

*

20

016

X<>Y

34

017

>H

43, 2

018

TAN

25

019

X<>Y

34

020

TAN

25

021

CHS

16

022

*

20

023

COS^1 (ACOS)

43, 32

024

>RAD

42, 3

025

2

2

026

4

4

027

*

20

028

π

43, 26

029

÷

10

030

>H.MS

42, 2

031

RTN

43, 32

Example:
Los Angeles,
April 17. Latitude of 34°03’ N, 27 days
after March 21.
Result: approximately 12.5735 (12 hours, 57 minutes,
35 seconds)
Sydney, June
21. Latitude of 33°51’31” S (enter as
33.5131), 92 days after March 21.
Result: approximately 9.4439 (9 hours, 44 minutes, 39
seconds)
Rome,
September 1. Latitude of 41°51’ N, 164
days after March 21.
Result: approximately 12.5323 (12 hours, 53 minutes,
23 seconds)
This blog is
property of Edward Shore. 2016
According to the User's Manual Page 14 example of the basic programing about
ReplyDeletethe time an object takes to fall to the ground.
I try to find the exact second from the distance in meter.
Second Height (Meter)
1 4.9
2 19.6
3 44.1
4 78.4
Percent difference between 4.9 to 19.6 is 300% when add 78.4 + 300% = 313.6
313.6 meter using the programed formula equal to 8 second
8 313.6
16 1254
32 5016
64 20064
128 80256
the number in seconds is 8, 16, 32, 64, 128 look like a computer bits numbers.
Just curious and share the though.....