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 formula for angular momentum is L = Iω, where I is the moment of inertia and ω is the angular velocity.

To find the moment of inertia, we can use the formula for a solid disk rotating around its center: I = (1/2)MR^2, where M is the mass and R is the distance from the center to the edge.

Plugging in our values, we get:

I = (1/2)(5.0 kg)(2.0 m)^2 = 10 kg·m^2

Now we can calculate the angular momentum:

L = Iω = (10 kg·m^2)(3.0 rad/s) = 30 kg·m^2/s

Therefore, the answer is D) 60.

A Puck on a Frictionless Air Hockey Table Has a Mass