This video evaluates the double integrals, utilizing polar coordinates, found in the video.
• Find the Region of a Circle with a Missing...
It then proceeds to use the results to find the center of mass of a circle with a missing segment.
The inner integrals are evaluated first along r summing all the infinitesimally small slices dr, followed by the evaluation of the outer integral from 0 to alpha and then from alpha to pi/2. This sums all the infinitesimally small slices of d(theta). The results of the double integrals are then summed. This gives the weighted average of x over the uniform region. Dividing this by the area of the region gives the center of mass of the region.
The calculations re check by setting appropriate values for a and b.