Question

A circular disc of radius r has a uniform thickness . a circular hole of diameter equal to the radius of the disc has been cut out . find the center of mass of the remaining system . take co-ordinates of center of main body as (0,0).

Answer 1

Answer:

An illustration of the helium atom, depicting the nucleus (pink) and the electron cloud distribution (black). The nucleus (upper right) in helium-4 is in reality spherically symmetric and closely resembles the electron cloud, although for more complicated nuclei this is not always the case. The black bar is one angstrom (10−10 m or 100 pm).