PLZ HELP: what is the mass of a rolling ball going down a hill at 4.05 mph with a slope of 2.2?

Question

iwanttogotostanford · Answer

@imqwerty @Nnesha

iwanttogotostanford · Answer

@dayakar @Alphabet_Sam please help if you can

iwanttogotostanford · Answer

@Michele_Laino

michele_laino · Answer

here we have to apply the theorem of Huyghens-Steiner. Namely the moment of inertia of each mass with respect to the rotation axis, is given by the moment of inertia with respect to the ice skater plus the product of such mass times the square of the distance between the ice skater and that rotation axis

iwanttogotostanford · Answer

oh ok, what formula would I use for that?

michele_laino · Answer

do we know the radius of the ice rink?

iwanttogotostanford · Answer

nope, everything I know is in this exact problem

iwanttogotostanford · Answer

not sure what to do next

michele_laino · Answer

I'm thinking...

michele_laino · Answer

we can write this:
the moment of inertia of both masses, with reapect to the ice skater is:
$$\Large  {I_0} = 2m{d^2}$$
where $m=2$ and $d=0.6$
After that, when the ice skater pulls her arms, she make a work, and such work increases the kinetic energy of such ice skater

iwanttogotostanford · Answer

@AihberKhan

aihberkhan · Answer

I really am not sure... I am really sorry!

iwanttogotostanford · Answer

I know the equation,,,, just need help applying it

iwanttogotostanford · Answer

@pooja195

triciaal · Answer

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