Q. A disturbing mass m1 attached to the rotating shaft may be balanced by a single mass m2 attached in the same plane of rotation as that of m1, such that (where r1 and r2 are the radii of rotation of m1 and m2 respectively)

• (A) m1r2 = m2r1
• (B) m1r1 = m2r2
• (C) m1m2 = r1r2
• (D) None of these