Physics

Problem

A system consists of three point masses constrained to move along the

x

-axis. A mass

m

is fixed at

x=0

, a mass

2m

is fixed at

x=L

, and another mass

m

can slide freely between the two fixed masses. Let

x

be the position of the sliding mass, measured from the origin, where

0\le x\le L

. Which expression gives the

x

-coordinate of the center of mass of the three-mass system in terms of

x

and

L

? a)

\dfrac{L + 2x}{4}

\dfrac{2L + x}{4}

\dfrac{L + x}{3}

\dfrac{2L + x}{3}