**Answer:**

The angular speed of the system at the instant when the rings reach the ends of the rod is 2.93 rev/min.

**Explanation:**

**Given that,**

Mass of rod

Length = 0.350 m

Mass of small ring = 0.240 kg

Distance

Angular velocity = 25.0 rev/min

**Suppose we calculate the angular speed of the system at the instant when the rings reach the ends of the rod**

**We need to calculate the moment of inertia of rod**

**Using formula of moment of inertia**

Put the value into the formula

**We need to calculate the moment of inertia of the rings when they are at a distance r₁**

**Using formula of moment of inertia**

Put the value into the formula

**We need to calculate the moment of inertia of the rings when they are at a distance r₂**

**Using formula of moment of inertia**

Put the value into the formula

**We need to calculate the angular speed of the system at the instant when the rings reach the ends of the rod**

**Using conservation of angular momentum**

Put the value into the formula

**Hence, The angular speed of the system at the instant when the rings reach the ends of the rod is 2.93 rev/min.**