Skip to main content.

Hint to puzzle 4: Equatorial belt

  1. Write an equation connecting d, the extra belt length; r, the radius of the Earth; 2a, the length of the belt not in contact with the Earth; and x, the angle subtended at the center of the Earth.
  2. Draw a radius from the center of the Earth to one of the points of contact between the Earth and the belt.  What angle is made between the radius and the belt?
The Earth, radius r, with equatorial belt, rising to height h above the surface. The belt is also shown meeting the Earth, at a tangent.