Where to apply concept of reduced mass?

Question

Where can i apply the concept of reduced mass in kinematics, i saw some examples but didnt seem to get it(looks like am a bit idiot in this concept). Please explain it in brief and simple english .

Answer 1

In physics, the reduced mass is the "effective" inertial mass appearing in the two-body problem of Newtonian mechanics.

Quote from Wikipedia page on Reduced Mass. I highly suggest that you read through this page.

As mentioned above, the concept of reduced mass appears when you try to solve two-body problems. The working idea is to convert the two Equation of motion on each mass to a single equation by a change of coordinates. The reduced mass is exactly the mass that appears in this single equation.