Question

If the Earth were flat and not curved then which will get more heat - Japan or Equator, or both equally?

Answer 1

both of them will be equally heated

Answer 2

Explanation:

Topography defines a land area's physical characteristics. Typically, these characteristics include natural formations like hills, rivers, lakes, and valleys. It may also include manmade characteristics such as highways, dams, and towns. Topography often uses a topographical map to record the different elevations of an region.

There will be no curved topography above the earth's surface when the earth is flat.  Because of this Earth's flat nature, all locations on Earth will be similarly heated regardless of whether it is Japan or Equator.  Japan and the equator will also be similarly heated in that situation.