Wednesday

July 30, 2014

July 30, 2014

Posted by **john** on Saturday, March 17, 2012 at 11:20pm.

(a) What is the moment of inertia (kg/m2

) of a solid cylinder rotating about an axis parallel to the symmetry axis but passing through the edge of the cylinder?

(b) What is the moment of inertia (kg/m2

) of a solid sphere rotating about an axis tangent to its surface?

The wording in (a) is confusing me. I tried but wasn't even close on both.

- Physics Please help! -
**Adam**, Tuesday, March 25, 2014 at 9:27pmUsing the parallel axis theorem, we know that I = I_cm + mr^2, where r is the amount of displacement from the symmetry axis.

And we know that for a solid cylinder, I_cm = 1/2(mr^2); Further, for a solid sphere I_cm = 2/5(mr^2)

(a)

==> I = 1/2(mr^2) + mr^2 = 3/2(mr^2) = 3/2(7.99)(.075^2) = 6.7416E-2 kg

(b)

==> I = 2/5(mr^2) + mr^2 = 7/5(mr^2) = 7/5(7.99)(.075^2) = 6.2921E-2 kg

**Related Questions**

Physics Please help! - In each of the following cases, the mass is 7.99 kg and ...

Physics - What is the moment of inertia of an object that rolls without slipping...

Physics - A 90kg stuntman falls from a building that is 80 meters tall. (Vo = 0)...

physics - A 90kg stuntman falls from a building that is 80 meters tall. (Vo = 0...

Please check solution - A uniform solid disk with a mass of 40.3 kg and a radius...

12th grade - A bicycle wheel has a radius of 0.330 m and a rim whose mass is 1....

Physics Inertia : Merry-go-round - A playground merry-go-round of radius 1.96 m ...

Physics review - So I've already found/ was given the radius, hanging mass, and ...

Physics - A yo-yo is spun from rest by pulling on the string with a constant ...

astronomy - Rank the following hypothetical planets -- all of which have the ...