Four Identical Particles, Each with Mass M, Are Arranged in the X

Multiple Choice

Four identical particles, each with mass m, are arranged in the x, y plane as shown. They are connected by light sticks to form a rigid body. If m = 2.0 kg and a = 1.0 m, the rotational inertia of this array about the y-axis is:

A) 4.0 kg . m²
B) 12 kg. m²
C) 9.6 kg . m²
D) 4.8 kg . m²
E) none of these