A puck on a frictionless air hockey table has a mass of 5.0 kg and is attached to a cord passing through a hole in the surface as in the figure. The puck is revolving at a distance 2.0 m from the hole with an angular velocity of 3.0 rad/s. The angular momentum of the puck (in kg.m²/s) is: A)80 B)20 C)30 D)60 E)50

Question

Quizplus · Accepted Answer

The angular momentum of the puck can be calculated using the formula L = Iω, where I is the moment of inertia and ω is the angular velocity. For a point mass rotating at a distance r, the moment of inertia is I = mr^2. Plugging in the given values, we get:

I = (5.0 kg)(2.0 m)^2 = 20 kg·m^2
L = Iω = (20 kg·m^2)(3.0 rad/s) = 60 kg·m^2/s

Therefore, the angular momentum of the puck is 60 kg·m^2/s. The closest answer choice is D) 60.

A Puck on a Frictionless Air Hockey Table Has a Mass