Circle
the correct answer. There is 1 (and only 1) correct answer for each.
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Problem 1
What is
the angular velocity of a point on an object that is in uniform rotational
motion with a frequency of 60 revolutions per minute?
a. 120
radians/sec
b. 2
radians/sec
c. 30
radians/sec
d. 30
p
radians/sec
e. 2
p
radians/sec
ANSWER
(60
rev/min)1
min/60 sec)(2
prad
/rev
w
= 2
p
radians/second from dimensional analysis
also,
since
w
= 2
p
f and f (the frequency) = 60 rev/min = 1 rev/sec
w
= 2
p
1 = 2
p
radians from the above relationship
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Problem 2
The
conservation of angular momentum of a rotating body states that the total
angular momentum is conserved as long as
a. There
is no torque acting on a rotating body
b. The
rotating body is rotating clockwise
c. The
rotating body is rotating counterclockwise
d. There
is no net torque acting on a rotating body
ANSWER
Fill the
the blanks for the following
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The moment of inertia, I, of a particle of mass m that is a distance
r from the center of a rotating body is
given by
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_______________________
is a measure of an object's resistance to change in its rotation rate.
Moment of Inertia
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The angular momentum, L, of an object rotating with an angular
velocity of
w
about a fixed axis of
rotation and a moment of inertia of I about the axis is given by
L = Iw