JEE MainPhysicsCenter of MassMCQ+4 / −1
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 the system is at a point: 

- A2.0 cm right and 0.9 cm above 1 kg mass
- B0.9 cm right and 2.0 cm above 1 kg mass
- C0.6 cm right and 2.0 cm above 1 kg mass
- D1.5 cm right and 1.2 cm above 1 kg mass
View written solutionFree
Correct answer: B
- Set up coordinates
Take the mass as the origin.
From the usual right triangle arrangement shown:
- at
- at cm
- at cm
This matches the -- right triangle.
Total mass:
- Use center of mass formula
The coordinates of center of mass are
- Compute -coordinate
- Compute -coordinate
- Interpretation
So the center of mass is at
- Compare with options
Given options:
- A:
- B:
- C:
- D:
None matches exactly. The closest is option D if coordinates were interchanged approximately, but it is still not correct.
Hence, based on the standard interpretation of the figure, none of the listed options is correct.
If the masses at the other two vertices were swapped:
- at
- at
then which gives option A.
So the stored answer does not agree with the physics calculation under either natural placement.
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