Cycle II AP Physics

John  Dewey High School

Mr. Klimetz

Conceptual Problem in Rotational Dynamics

Solve the following conceptual problem on rotational dynamics in the space provided at the bottom of this page. Your answer can be either verbal, graphical, mathematical, or a combination of all. You should also create a sketch of the situation to assist you in your solution. Be patient. Think sensibly, rationally, and in accordance with the principles of rotational dynamics.

A solid metal sphere with diameter of R centimeters rolls without slipping down an incline of vertical height H and angle of inclination theta.  A greased, solid glass box with a height of R centimeters slides down the same incline without friction. If both objects are released from the top of the incline at the same time, which object will reach the bottom of the incline first?

Useful Rotational Dynamics Equations

KEtranslational = mvexp2/2

KErotational = Iwexp2/2

KEtotal = mvexp2(CM)/2 + Iwexp2(CM)/2

Solution: