Siclas Sifilis

1

F´
ısica de los Materiales
Harol Valencia Mart´nez
ı
Rotaci´n y Cuerpo R´
o
ıgido
Octubre 4 de 2010
(Taller II y III)

1. During a certainperiod of time, the angular position of swinging door is described
by:
θ(t) = 5 + 10t + 2t2
θ where is in radians and t is in seconds. Determine the angularposition, angular
speed, and angular acceleration of the door a) at t = 0 s b) at t = 3.00 s.
2. An airliner arrives at the terminal, and the engines are shutoff. The rotor of one of the
engines has an initial clockwise angular speed of 2 000 rad/s. The engine’s rotation
slows with an angular acceleration of magnitude80.0 rad/s2 .
a) Determine the angular speed after 10.0 s.
b) How long does it take the rotor to come to rest?
3. A wheel 2.00 m in diameter lies in avertical plane and rotates with a constant angular
acceleration of 4.00 rad/s2 . The wheel starts at rest at t = 0, and the radius vector of
a certain point P onthe rim makes an angle of 57.3◦ with the horizontal at this time.
At t = 2.00 s, find
a) the angular speed of the wheel,
b) the tangential speed and thetotal acceleration of the point P, and
c) the angular position of the point P.
4. Two balls with masses M and m are connected by a rigid rod of length L andnegligible
mass as in Figure 1. For an axis perpendicular to the rod, show that the system has
the minimum moment of inertia when the axis passes through thecenter of mass.
Show that this moment of inertia is
mM
I = µL2
con
µ = m+M

Figura 1:

The previous exercises are taken from 6 ed Serway y Jewett