Practice question
Question
Four particles of masses 1kg, 3kg, 5kg, and 7kg are at (0,0), (2,0), (0,3), and (2,3) respectively. What is the y-coordinate of their center of mass?
Explanation
Formula: Y = m1y1+m2y2+m3y3+m4y4m1+m2+m3+m4. Masses: 1,3,5,7kg; y-coordinates: 0,0,3,3. Y = (1×0)+(3×0)+(5×3)+(7×3)1+3+5+7 = 0+0+15+2116 = 3616 = 2.25m. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 2.25 m. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.