Ive been running TSD rallys for a while now and I have never been able to get the math to work out to calculate a time given a target speed and a delta mileage.
i.e.: 34mph (covering a distance of) .65 miles = X.XX minutes
I have tried and i can’t get the math to work out (damn standard units on top of time conversions) and a conversion to metric induces further errors. I have tried using unit conversion and using 60mph over 1.000 mile = 1.00 minutes, 30mph -> 2.00 minutes, 120 -> 0.50 minutes and I can’t get the math to check out.
Scoring is done based on minutes w/ a decimal (minutes and tenths/hundredths/thousandths of a minute) and we need a human readable minutes:seconds time. Any help doing that would be nice too.
I am severely humbled to ask all this, having scored well in high school physics, aced a similar college phyiscs course, and slept thru and aced a conceptual physics course. I should know how to do this and I can’t.
As long as you don’t mix units, all you really need are these three equations, which of course are derived from each other. Pick the one that takes the fewest steps to get to the solution:
Oh, and if you have a SHARP EL-546G scientific calculator handy. (I think any SHARP EL-500 Series should be able to do this) After finding out the time in hours, using the t = d / v formula, and noting that miles will divide out and hours will remain…
You can just use the hours decimal of
0.019117647
and press the Degree,Minute,Seconds button
or D°M’S button located at the fourth row and third column.
This button will convert any number in decimal form into degrees (or hours), minutes and seconds, with 2 places for the milliseconds spot.
so you end up with 0°01’08.82 on the display of the calculator.
If you don’t have a scientific calculator that can do this function just stick with my previous post’s method and all should be fine.
Here is what I call an “Ultra Calculator” from my website. http://www.1728.com/velocity.htm
It deals with velocity, time and distance. You can input each of these three variables from dropdown menus offering twelve units each.
example: you can enter velocity in
cm/sec;
feet/minute;
feet per second;
inches per second;
km per hour;
kilometers per second;
knots;
metes per second;
miles per hour;
miles per minute;
miles per second; and
millimeters per second.
Basically enter any 2 of the 3 quantities and you’ll get the third (also calculated in a list of 12 units).
Any small airport can give you a flighttime calculator. You read instructions, rotate distance to speed, look at time. It is a slide rule thingie, but that was how I learned. No calculators in my schools.
Or, 60miles per hour for sixty minutes = 60 miles…Do not change your units. Or change your units to this and then change the result to your liking. The units rule the equation. The equation rules under earlier postings.