Centre of gravity and Midpoint

Centre of gravity noun - The point within something at which gravity can be considered to act; in uniform gravity it is equal to the center of mass.

Midpoint and centre of gravity are semantically related. In some cases you can use "Midpoint" instead a noun phrase "Centre of gravity".

Midpoint noun - A middle point between extremes.

Centre of gravity and midpoint are semantically related. Sometimes you can replace phrase "Centre of gravity" with "Midpoint", this terms are similar.