How is the acceleration of an object in uniform circular motion constant?

The image below shows numerous volcanic mountains in the pacific northwest. what is the most likely cause of the volcanic and earthquake activity in this region?

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

The radius of an atom is closest in size to a