Ask a Geography Question 10, Ask a Geography Question

Literature source】 Middle School Geography Teaching Reference, Teaching Reference of Middle School Geography, Department Mailbox, 2005, Z2.

Journal honors: Overview of Chinese core journals aspt** journal cjfd included abstract] "Zheng" [Example 1] Regardless of sea and land, terrain, ice and snow and other conditions, someone starts from a place near the pole (including the pole) and walks 5 kilometers to the north, 5 kilometers to the east, and 5 kilometers to the south, just back to the original place. From the sky above the pole, it may be a

Clockwise walked a full circle bCounterclockwise went a full circle cClockwise walked an arc less than 360 d

Counterclockwise arc less than 360 is difficult to parse, you must give full play to your imagination and think about the problem from multiple angles in order to find a suitable answer. There are two possibilities depending on the question requirements.

I think this topic chooses C, because the title says that it contains the pole, to the north, so it can only be the South Pole, from the South Pole to the north 5 kilometers, and then to the east 5 kilometers, (the direction of rotation of the earth is from west to east, from the north pole is counterclockwise, from the south pole to the clockwise, simply recorded as north and south south,) so go due east 5 kilometers is clockwise, and then go due south 5 kilometers, just back to the south pole, I don't know if I answered correctly, for the answer.

The first thing to know is that the actual is a complete circle that has been walked counterclockwise.

If it is the Northern Hemisphere, you can only walk near the pole (because the question says to go due north), which means that you have walked a complete circle counterclockwise.

If it is the South Pole, it can only be walked from the South Pole, which is a clockwise arc less than 360°.

By: The Sorcerer Level 4 2-14 16:02

Someone starts near the pole (including the pole) and walks 5 km due north, 35 km due east, and 5 km due south exactly back to where they are

From the sky above the pole, it is possible to walk east:

A: Walked a circular arc less than 180 degrees counterclockwise

b: Clockwise walked an arc less than 180 degrees

c: Clockwise arc less than 360 degrees

d: Clockwise walked an arc greater than 360 degrees

Pick D. First of all, if you go north, it must be the South Pole.

Facing north, the right hand side is east, so it should be clockwise from the pole.

If you are near the pole, an arc of 35 kilometers can be considered a straight line and cannot form a triangle, so it must be an arc greater than 180 degrees.

Then I think about whether the circumference at that latitude is greater than 35 kilometers. If you think of the pole as the vertex of an equilateral triangle, 5 km is the waist of the equilateral triangle (it would be better if you drew a diagram).

The plane and pole of the 35-kilometer circle form a circular vertebrae, and 5-kilometer is the waist of the circular vertebrae, so the distance of the 5-kilometer projection at the bottom of the circular vertebra is a certain 5 kilometers, and this projection can be set as r.

The circumference of the circle is 2 radius.

2 3 14 5 31 4 35 km.

and r must be less than 5 km.

The circumference of a circle with r radius must also be less than 35 km.