Rotational Motion Question 163

Question: (n1) equal point masses each of mass m are placed at the vertices of a regular n-polygon. The vacant vertex has a position vector a with respect to the centre of the polygon. The position vector of centre of mass is

Options:

A) 1(na)a

B) a(n+1)

C) an

D) na+1

Show Answer

Answer:

Correct Answer: A

Solution:

[a] Let the C.M.

be ‘b’.

Then,

(n1)mb+mamn=0b=1n1a



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