View Full Version : OT: math problem-- 2 related physical problems

jeric_synergy

12-18-2014, 01:52 AM

Hey, MATH PEOPLE!:

2 related problems: you're cutting a pipe at an angle. What's the formula for determining the angle to achieve a specific >length< of cut? IOW, 90°=diameter of pipe, 0°=infinite.

2nd (and real problem): you have a plate you want to fit tilted at an specific angle over a pipe. How long is the oval slot you need to cut in the plate? (Supply a generic equation.)

THANKS!!!! :bowdown:

spherical

12-18-2014, 03:25 AM

My first question is: Why do you care? You're working with a 3D application. Put the pipe in a foreground layer, the plate in a background layer, position them at the angle you want, Boolean (or not) and measure.

RebelHill

12-18-2014, 04:34 AM

Use trig.

jeric_synergy

12-18-2014, 09:38 AM

My first question is: Why do you care?

OT: math problem-- 2 related physical problems

Use trig.

Oh, I thought I'd use a harpsichord.

Kryslin

12-18-2014, 09:40 AM

Probable answer for 2)

The resulting slice will be an ellipse; Major axis will be pipe radius / Sin (Angle), minor axis is pipe radius.

(Sine is used because Sin 90 = 1; Sin 0 = 0; At a 45 degree cut (.78539816 Radian), and a radius of 1, Major Axis = 1.414213, Minor Axis = 1.000).

So, The answer to number 1) should follow from above...

Length of Cut = Pipe Diameter / Sin (Angle)

Sin(Angle) * Length of Cut = Pipe Diameter

Sin(Angle) = Pipe Diameter / Length of Cut

Angle = Sin-1(Pipe Diameter / Length of Cut). Valid only if Length of Cut >= Diameter (Sin-1 only returns a valid value if it's input is 0...1)

jeric_synergy

12-18-2014, 09:45 AM

Probable answer for 2)

Thank you Kryslin.

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