Okay I rechecked the book and tried to work out a similar problem
I set the location of each mass on the x-axis with Mass A at 0, Mass B at 5 in the +x direction and Mass C at 12 in the + x direction
I applied that Xcm= mAxA+mBxB+mCxC/ mA+mB+mC= 7 m
To find the location of the center...
Three Balls are moving along a straight line having the instantaneous positions shown in figure 8.15. At that instant, find the location and velocity of the center of mass of this system.
Figure 8.15
Mass A---------------------Mass B-----------------------------------Mass C...