A) \[Y=-5cm\]
B) \[Y=+20cm\]
C) \[Y=+5cm\]
D) \[Y=-20cm\]
Correct Answer: A
Solution :
Before explosion, particle was moving along X-axis, i.e. It has no Y-component of velocity therefore, the centre of mass will not move in Y-direction or we can say \[Ycm=0\]. (Here note the wind explosion in due to only the internal forces) Now, \[Ycm=\frac{{{m}_{1}}{{Y}_{1}}+{{m}_{2}}{{Y}_{2}}}{{{m}_{1}}+{{m}_{2}}}\] Therefore, \[0-\frac{\left( \frac{m}{4} \right)(15)+\left( \frac{3m}{4} \right)(Y)}{\left( \frac{m}{4}+\frac{3m}{4} \right)}\] or \[Y=-5cm\] (negative sign shows the downward distance) Similarly the change in X-coordinate of the centre of mass will also be zero.You need to login to perform this action.
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