Nomad puzzle, can you solve in Inventor?

[Anonymous]

I played with this a bit, starting out drawing a sphere, but I would like to know how you guys can solve this nomad puzzle in inventor:

In spring, a nomadic tribe moves 100 km to the east.

In summer, the tribe moves 100 km to the north.

In autumn, the tribe moves 98 km to the west.

In winter, the tribe moves 100 km to the south.

The tribe reached its exact starting point from the spring and sets up its winters quarters there.

At what latitude Ø are the winters quarters (in degrees)? Round to the nearest integer.

Note: Earth's radius is R=6371 km.

I am using IV professional 2015.

[Xun.Zhang]

Hi Mike,

It's pretty easy to leverage command split to create a trail on a surface and then you can leverage sweep or loft to do more with the trail. please refer to enclosed file for a reference.

hope it helps!

[SBix26 · Accepted solution]

I suppose it's possible, but you'd have to scale the problem down considerably, since Inventor gets unstable with values in the 1 km range, let alone in the 6000 km range.  Possibly you could just work in mm or cm or inches using the values in the problem for km.  The units don't matter since your answer is going to be in degrees anyway.

In any case, I don't have Inventor 2015, but here's how I worked out the answer in Inventor, using just a single sketch:

This depends on recognizing that the northern arc is 98% the distance of the southern arc, and that the radii of those two arcs are in the same ratio.  So my solution above is just to set the lower radius to a driven dimension, and the upper radius to 98% of it.  The d1 dimension is actually the arc length, not a linear dimension.  Hope this helps (and is the correct answer!).

Sam B
Inventor Pro 2018.2.3 | Windows 7 SP1
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