Sample Problem
The three particles in are initially at rest. Each experiences an external force due to bodies outside the three system. The directions are indicated. and the magnitudes.
SOLUTION: The position of the center of mass, calculated by the method is marked by a dot in the figure. One Key Idea here is that we can treat the center of mass.
in the positions shown, are acted on by the external forces
shown. The center of mass (com) of the system is marked.
(b) The forces are now transferred to the center of mass of the
system, which behaves like a panicle with a mass M equal to the
total mass of the system. The net external force Foel and the acceleration
a,’om of the center of mass are shown.
We can evaluate the right side of directly on a vector capable calculator. or we can rewrite in component form. find the components. Along the x axis. we have,
