Question

What is the center of mass of a semi-circular disk?

1) At the center of the disk
2) At the midpoint of the diameter
3) At the edge of the disk
4) Cannot be determined

Answer 1

The center of mass of a semi-circular disk is located along the axis of symmetry, at a distance of 4R/(3π) from the center towards the flat edge of the disk.

Step-by-step explanation:

The center of mass of a semi-circular disk is not at the center of the disk, at the midpoint of the diameter, or at the edge of the disk. Instead, the center of mass for a semi-circular disk of radius R is located along the axis of symmetry of the disk on the side of the flat diameter, and it is at a distance of 4R/(3π) from the center towards the flat edge. This can be derived from the symmetry of the object and the definition of the center of mass. The center of mass is the point where we can consider the entire mass of an object to be concentrated for the purposes of physical analysis.