Calculus-Based Physics by Jeffrey W. Schnick - HTML preview
PLEASE NOTE: This is an HTML preview only and some elements such as links or page numbers may be incorrect.
Download the book in PDF, Kindle for a complete version.
Download the book in PDF, Kindle for a complete version.
Chapter 5 Conservation of Angular Momentum
Example 5-1
A skater is spinning at 32.0 rad/s with her arms and legs extended outward. In this
position her moment of inertia with respect to the vertical axis about which she is
spinning is
2
45 6
. kg ⋅ m . She pulls her arms and legs in close to her body changing
her moment of inertia to
2
17.5 kg ⋅ m . What is her new angular velocity?
BEFORE
AFTER
rad
w = 32.0
w ′ = ?
s
I
= 45.6 kg⋅m2
I′ = 17.5 kg⋅m2
L
= L′
Iw = ′
Iw′
I
w′ =
w
′
I
45 6
. kg ⋅ m2
w′ =
32.0 rad / s
17 5
. kg ⋅ m2
rad
w′ = 83.4 s
28