High School

If a trapeze artist rotates once each second while sailing through the air, and contracts to reduce her rotational inertia to one-fourth of what it was, how many rotations per second will result?

Answer :

Answer:

There are finally 4 rotations per second.

Explanation:

If a trapeze artist rotates once each second while sailing through the air, and contracts to reduce her rotational inertia to one fourth of what it was. We need to find the final angular velocity. It is a case of conservation of angular momentum such that :

[tex]I_1\omega_1=I_2\omega_2[/tex]

Let [tex]I_1=I[/tex] , [tex]I_2=\dfrac{I}{4}[/tex] and [tex]\omega_1=1[/tex]

So,

[tex]\omega_2=\dfrac{I_1\omega_1}{I_2}[/tex]

[tex]\omega_2=\dfrac{I\times 1}{(I/4)}[/tex]

[tex]\omega_2=4\ rev/sec[/tex]

So, there are finally 4 rotations per second. Hence, this is the required solution.

Final answer:

When a trapeze artist reduces their rotational inertia to one fourth while rotating, their rotational speed increases to four times its original rate to conserve angular momentum, resulting in 4 rotations per second.

Explanation:

The question pertains to the conservation of angular momentum, which is a principle in physics stating that if no external torque acts on an object, the total angular momentum will remain constant. For a trapeze artist or any rotating body, if the moment of inertia decreases, the rotational speed (number of rotations per second) must increase proportionally to conserve angular momentum.

If a trapeze artist is rotating once each second and contracts to reduce the rotational inertia to one fourth, her rotational speed must increase to four times what it was to conserve angular momentum. Therefore, the new rotation rate will be 4 rotations per second.