question_answer

Three point particles of masses 1.0 kg, 1.5 kg and 2.5 kg are placed at three corners of a right angle triangle of sides 4.0 cm, 3.0 cm and 5.0 cm as shown in the figure. The center of mass of system is at a point

[JEE MAIN Held on 07-01-2020 Morning]

A)   1.5 cm right and 1.2 cm above 1 kg mass

B)   2.0 cm right and 0.9 cm above 1 kg mass

C)   0.9 cm right and 2.0 cm above 1 kg mass

D)   0.6 cm right and 2.0 cm above 1 kg mass

Correct Answer: C

Solution :

[c]

\[{{X}_{cm}}=\frac{1\times 0+1.5\times 3+2.5\times 0}{1+1.5+2.5}=\frac{1.5\times 3}{5}=0.9\,cm\]

\[{{Y}_{cm}}=\frac{1\times 0+1.5\times 0+2.5\times 4}{1+1.5+2.5}=\frac{2.5\times 4}{5}=2\,cm\]