Auniform rod of mass 3.00×10−2 kg and length 0.350 m rotates in a horizontal plane

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.

Plant A

Explanation: The control group is participants who do not receive the experimental treatment.