Milo Martian
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But won't mechanical energy change due to friction? just curiousllober said:I think is better to do an Energy balance...
https://www.physicsforums.com/attachments/104346
The discussion centers on the dynamics of a solid sphere versus a hollow sphere of equal mass (M) and radius (R) rolling down an incline without slipping. Key equations include the center of mass acceleration (acm = Fext/M) and the moments of inertia for the hollow sphere (Ihollow = 2MR²/3) and solid sphere (Isolid = 2MR²/5). The solid sphere accelerates faster due to its lower moment of inertia, leading to a higher angular acceleration despite both spheres experiencing the same net external force. The confusion arises from the relationship between translational and rotational motion in pure rolling scenarios.
PREREQUISITESPhysics students, educators, and anyone interested in classical mechanics, particularly in understanding the dynamics of rolling objects on inclines.
But won't mechanical energy change due to friction? just curiousllober said:I think is better to do an Energy balance...
https://www.physicsforums.com/attachments/104346
If there's no sliding, there's no loss by friction, because the no sliding translates into speed zero at the contact point, so the "friction force" does not move.Milo Martian said:But won't mechanical energy change due to friction? just curious
OKllober said:If there's no sliding, there's no loss by friction, because the no sliding translates into speed zero at the contact point, so the "friction force" does not move.
You got it.Milo Martian said:Okay, i got it .
Fext= mgsinA - f= macm ...(1)
fXR= torque = I X angular acc. = I X acm/R
=> f= Iacm/R2 ...(2)
From (1) and (2) :
macm = mgsinA - Iacm/R2
=> acm= mgsinA/(m + I/R2)
So, since Isolid sphere< Ihollow sphere
Therefore, acm for solid sphere> acm for hollow sphere.
i hope i am right. phew