Put ice in the top one.. and put the bottom one in hot water. Top one pops right out!
More like two tetrahedrons stuck together.
Octahedron https://en.wikipedia.org/wiki/Octahedron
Eight sided three-dimensional shape. Often this looks like two pyramids stuck together at their bases.
A hexahedron or a triangular dipyramid. This is the shape formed by two triangular pyramids (tetrahedrons) stuck together along one triangular face.
Put ice in the inside one and rub the out one. The ice will result in thermal contraction and the friction in thermal expansion. Neither will be large but should be sufficient.
heat them (with a lighter, or the oven or sumthin), then slide slowly away from each other.
Stuck together.
A molecule
Two amplifiers stuck together.
two cat fish stuck together
lute
Siamese twins
10cm2
two pairs of glasses
More like two tetrahedrons stuck together.
The rubbing generates Static Electricity charges, and since the positive and negative attract each other, the two balloons stick together.
They do no such thing