ADDITIONS TO HRW PROBLEMS AND PROBLEMS FROM OTHER TEXTS
JUNE 18 - JUNE 24
HRW - CHAPTER 11
58. You must do problem 58 twice, once using Newton's Laws,
and once using Conservation of Energy. So add parts
(c) and (d), in which you use Newton's Laws instead of
Energy Conservation to do exactly the same problem as
in (a) and (b).
Fishbane - CHAPTER 9
45. A wheel of radius 24.6 cm whose axis is fixed starts
from rest and reaches an angular velocity of 4.15 rad/s
in 2.68 s due to a force of 13.4 N acting tangentially
on the rim. (a) What is the rotational inertia of the
wheel? (b) What is the change in the angular momentum
during the 2.68 s? (c) How many revolutions does the
wheel make? (d) How much rotational kinetic energy
does the wheel have after 2.68 s?
Fishbane - CHAPTER 10
13. A square, 20 cm on the side, is made of very light
sticks. Four identical masses of m = 0.1 kg form the
corners of the square. The square rotates with an
angular velocity of 8 rad/s about an axis perpendicular
to its plane through the center of the square.
(a) Calculate the rotational inertia of the system
about the rotation axis and use it to find the angular
momentum about this axis. (b) Use the general
definition of angular momentum to calculate the
angular momentum of each mass with respect to the
center of the square, and add these up. Compare the
results of (a) and (b).
PROBLEM G2
A metal ball is to be rolled down a track inclined
at an angle theta with respect to the horizontal,
starting from rest. The track is a pair of rails,
with the separation distance between the two rails
equal to the radius of the ball. (a) Find the
acceleration of the ball after it is released.
(b) Find a_x the horizontal component of the
acceleration of the ball after it is released.
(c) Find the angle theta for which a_x is a maximum.