Precession: An object is rotating with an angular momentum 4.00 kg ∙ m²/s while being acted on by a constant torque 3.00 N∙m . What is the angular speed of precession of the angular velocity of the object? A) 1.33 rad/s B) 0.750 rad/s C) 12.0 rad/s D) zero E) It depends on the moment of inertia of the object.

Question

Quizplus · Accepted Answer

The angular speed of precession is given by $\omega_p = \frac{|\vec{L}|}{|\vec{T}|}$, where $\vec{L}$ is the angular momentum and $\vec{T}$ is the torque. Plugging in the given values, we get $\omega_p = \frac{4.00	ext{ kg}\cdot	ext{m}^2/	ext{s}}{3.00	ext{ N}\cdot	ext{m}} = 1.33	ext{ rad/s}$. Note that the moment of inertia does not affect the equation, so option E can be ruled out.

Precession: an Object Is Rotating with an Angular Momentum 4