Physics 112
Homework #9
Spring 2006
*** Prelim Exam #2
is 7:30-9 PM onThursday evening, Apr. 6.
It covers chaps. #6-9 + secs. 10.3 (thru
Ex. 10.7) & 12.3, circular motion dynamics (sec. 5.4 + HW #5 problems), HWs #6-9, Labs #5 & 6 + Pre-
Labs, COOPs #6-8, and all relevant lecture material.
Persons with conflicts or special needs please
contact Edith Cassel ASAP.
***
Read:
Chapter 8 (sections 8.4, 8.5),
Chapter 9 (all)
Chapter 10 (only section 10.3 through Example 10.7)
For discussion:
Chap. 8: Qs #Q8.9, Q8.10, Q8.18, Q8.21;
(not turned in)
Chap. 9: Qs #Q9.4, Q9.5, Q9.6, Q9.9, Q9.10, Q9.12, Q9.13, Q9.18, Q9.19, Q9.21
Chap. 10:
Qs #Q10.15, Q10.17, Q10.18;
To be worked and discussed before Prelim Exam #2, but not turned in:
#8.65
[Railroad Handcar]
#9.52
[Parallel Axis Theorem]
#9.47
[Flywheel Energy Storage]
#9.89
#9.41
[Wagon Wheel]
Please add:
(b)
What is the wheel's
total
kinetic energy when rolling without
slipping at a speed of 3.0 m/s?
What fraction of this is
translational
KE?
What fraction is
rotational
KE?
(c)
If this wheel started rolling at 3.0 m/s up a hill of slope angle 20°, how far along the hill could it roll
freely without slipping until it came to rest?
1. [Melting the Polar caps]
The polar ice caps contain about 2.3 x 10
19
kg of ice. This mass contributes
essentially nothing to the moment of inertia of the earth because it is located at the poles, close to the axis