Four point masses are fixed at the corners of a rigid square frame that lies in the…
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
Four point masses are fixed at the corners of a rigid square frame that lies in the horizontal plane. Starting at the lower-left corner and moving clockwise around the square of side 0.40m, the masses are 0.20kg, 0.30kg, 0.20kg, and 0.30kg. A vertical axis passes through the geometric center of the square and is perpendicular to its plane.
(a) Choose a coordinate system whose origin is at the center of the square. Determine the (x,y) coordinates of each mass.
(b) Calculate the rotational inertia of the four-mass system about the given axis. Show all steps and include appropriate units.
(c) Suppose the four masses were each replaced by a single value equal to the arithmetic mean of the original four masses. Without performing another full calculation, explain qualitatively how the rotational inertia would compare to the value found in part (b).