List of top Physics Questions on System of Particles & Rotational Motion asked in DUET

The reduced mass of two particles having masses $m$ and $2\, m$ is

Two identical springs are connected in series and parallel as shown in the figure. If $ f_{s} $ and $ f_{p} $ are frequency of series and parallel arrangement what is $ \frac{f_{s}}{f_{p}} $ ?

A string of length $ l $ fixed at one end carries a mass m at the other end. The string makes $ \frac{2}{\pi } $ rev/s around the horizontal axis through the fixed end as shown in the figure, the tension in string is :