Rotational Motion (Inclined Plane)

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Homework Help Overview

The discussion revolves around a problem in rotational motion involving a solid cylinder and a solid sphere on an inclined plane. The original poster is trying to determine which object reaches the ground first, referencing their moments of inertia.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to understand the mathematical demonstration of their assertion regarding the sphere's descent. Some participants suggest using energy methods to analyze the problem, while others propose calculating kinetic energy at the bottom of the incline to compare velocities.

Discussion Status

Participants are exploring different approaches to the problem, with some guidance offered on using energy principles. The original poster indicates they have resolved their question independently, but the conversation continues with clarifications about related topics.

Contextual Notes

There is mention of an upcoming test, which may influence the urgency of the discussion. Additionally, there is a reference to AP Physics C, indicating a context of advanced physics education.

Izzybee
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[SOLVED] Rotational Motion (Inclined Plane)

Hi Everyone!
My question is: A solid cylinder and a solid sphere are resting on top of a inclined plane. Using mathematics, which object would reach the ground first. Given: I (cylinder) = 1/2mr ^2 and I (sphere) = 2/5 mr ^2.

I know that the sphere would reach the ground first because of its mass distribution, but I am not quite sure how to show it mathematically. My teacher said a problem like this will show up on my test Monday!

Please help!
 
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What is the energy of a rotating solid?
 
I think what kurdt's suggesting is to try using energy methods.

p.s. Are you taking AP Physics C?
 
CALCULATE THE KINETIC ENERGY OF THE CYLINDER AND THE SPHERE AT THE BOTTOM OF THE PLANE...AND THEN FIND WHICH OF THE TWO HAS THE GREATER VELOCITY...

THE ONE WITH GREATER VELOCITY IS THE ONE WHICH COMES DOWN EARLY..

USE THE FORMULA..

mgh=1/2mv^2(1+k^2/r^2)

K(RADIUS OF GYRATION)==I/M
 
Thanks, but I figured it out!
P.S: What is AP Physics C??
 
Advanced Placement college board course. Its an American thing I believe.
 
No I am not.
 

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