Thursday, January 14, 2016

HP 15C: Approximate Length of Sunlight During a Day



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 (degrees-minutes-seconds) 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


1 comment:

  1. According to the User's Manual Page 14 example of the basic programing about
    the 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.....

    ReplyDelete

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