When Slide Rules Ruled
Make your own slide rule
+
=
2 x 3
…………….
20 x 3
2 x 6
355/113
355/113 to 5 decimal places
Standard 10 inch Rule
355/113 = 3.14
20 inch Rule
355/113 = 3.14
Otis King66 inch Helical Rule
355/113 = 3.142
Fuller 41 foot Helical Rule
355/113 = 3.1416
The Cursor can be a simple indicator, or a memory
1.5 x 3 x 42
The CI (inverted C) scale is the reciprocal of the C scale, and
assists with chain multiplications and divisions.
1.5 x 3 x 42
You accidentally drop your i-phone from a height of 3.5 feet while
playing angry birds. How quickly must you react and catch it before it
is toast?
443.5DistanceTime
You are at an outdoor concert, standing 20 feet from an omnidirectional speaker where the loudness is 105 decibels. Your parents
say you must limit your exposure to 95 decibels. You double your distance from the
speaker. Is that far enough?2
2
1log10
DDdB
2
4020log1010
?
What is the sine of 0.02 radians?
What is Ln 1.006?
What is e-0.09?
Ln(1+x) = x – x2/2 + x3/3 - …
ex = 1 + x + x2/2! + x3/3! …
~ 0.02(0.019999)
~ 0.91(0.914)
Ln(1+x) = x – x2/2 + x3/3 - … ~ 0.006(0.00598)
ex = 1 + x + x2/2! + x3/3! …