Solving a Ball Roll Down a Slide: Velocity at Bottom

AI Thread Summary
To determine the velocity of a ball rolling down a slide of height 4 m, conservation of mechanical energy is the key principle to apply. The initial potential energy at the top of the slide converts into kinetic energy and rotational energy at the bottom. The moment of inertia for a thin spherical shell, Icm=(2/3)mr^2, is relevant for calculating the rotational kinetic energy. The discussion highlights confusion regarding the use of angular momentum versus energy in the context of this problem. Ultimately, applying the correct equations will yield the ball's velocity at the bottom of the slide.
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Homework Statement



A toddler is having fun rolling a ball down a slide of height h=4 m. The ball can be considered as a thin spherical shell, Icm=(2/3)mr^2, with m being its mass and r being its radius. What is the velocity of the ball at the bottom of the slide?

http://schubert.tmcc.edu/enc/51/76a002f3ae50dbbab12d33cf0762512f807c557c31b679999d542c0ad5867fc1faec19c5cc0644a0057420a72734c009d46cf669ed738b61fc0def4a303f9990.gif

Homework Equations



KE(i) + PE(i) + Iw(i) = KE(f) + PE (f) + Iw(f)

KE(i) = Initial Kinetic Energy
PE(i) = Initial Potential Energy
Iw(i) = Initial Inertia*Omega

KE(f) = Final Kinetic Energy
PE(f) = Final Potential Energy
Iw(f) = Final Inertia*Omega

The Attempt at a Solution



I think I am supposed to use the above equation but I am not quite sure. Any suggestions? Thanks.
 
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You want to use conservation of mechanical energy, don't you? But Iw is not energy. It is angular momentum.

ehild
 
So, what do I do with this value: Icm=(2/3)mr^2? I am sure that it plays a part in solving for the solution.
 

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