Two points masses of 2 kg and 3 kg lie at 5 m and 9 m away from origin O respectively. Find out the distance of centre of mass of these point masses from the origin.

Options

A. 14.2 m
B. 7.4 m
C. 20 m
D. 6 m

Answer

B

Explanation

Given, `m_(1)=2kg, m_(2)=3kg, x_(1)=5m, x_(2)=9m`
`therefore" Centre of mass,"`
`x_("CM")=(m_(1)x_(1)+m_(2)x_(2))/(m_(1)+m_(2))=(2xx5+3xx9)/(2+3)=(10+27)/(5)=(37)/(5)=7.4m`