Alvarado, Patrick – Homework 1 – Due: Sep 14 2006, 10:00 am – Inst: Andrei Sirenko
1
This
printout
should
have
19
questions.
Multiplechoice questions may continue on
the next column or page – find all choices
before answering.
The due time is Central
time.
001
(part 1 of 2) 10 points
A
record
has
an
angular
speed
of
50
.
4 rev
/
min.
What is its angular speed?
Correct answer: 5
.
27788 rad
/
s.
Explanation:
1 rev = 6
.
28319 rad, and
1 min = 60 s
,
Therefore,
ω
1
= (50
.
4 rev
/
min)
2
π
rad
rev
¶
1 min
60 s
¶
= 5
.
27788 rad
/
s
.
002
(part 2 of 2) 10 points
Through what angle, in radians, does it rotate
in 0
.
932 s?
Correct answer: 4
.
91898 rad.
Explanation:
θ
=
ω t
= (5
.
27788 rad
/
s) (0
.
932 s)
= 4
.
91898 rad
.
keywords:
003
(part 1 of 1) 10 points
A large wheel is coupled to a wheel with half
the diameter as shown.
r
2
r
How
does
the
rotational
speed
of
the
smaller wheel compare with that of the larger
wheel?
How do the tangential speeds at
the rims compare (assuming the belt doesn’t
slip)?
1.
The smaller wheel has four times the ro
tational speed and the same tangential speed
as the larger wheel.
2.
The smaller wheel has twice the rotational
speed and the same tangential speed as the
larger wheel.
correct
3.
The smaller wheel has half the rotational
speed and half the tangential speed as the
larger wheel.
4.
The smaller wheel has twice the rotational
speed and twice the tangential speed as the
larger wheel.
Explanation:
v
=
r ω
The tangential speeds are equal, since the
rims are in contact with the belt and have the
same linear speed as the belt.
The smaller wheel (with half the radius)
rotates twice as fast:
1
2
r
¶
(2
ω
) =
r ω
=
v
keywords:
004
(part 1 of 1) 10 points
Harry and Sue cycle at the same speed. The
tires on Harry’s bike have a larger diameter
than those on Sue’s bike.
Which tires have the greater rotational
speed?
1.
Sue’s tires
correct
2.
The rotational speeds are the same.
3.
It depends on the speed.
4.
Harry’s tires
Explanation:
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Alvarado, Patrick – Homework 1 – Due: Sep 14 2006, 10:00 am – Inst: Andrei Sirenko
2
v
=
r ω
. Tires with a smaller radius needs
a larger rotational speed to obtain the same
linear speed.
keywords:
005
(part 1 of 1) 10 points
A rigid circular wheel spins at constant angu
lar velocity about a stationary axis.
Choose
the picture below that correctly describes the
relative magnitudes and directions of the ve
locity vector of points on the wheel.
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 OPYT
 Acceleration, Work, Velocity, Correct Answer, Physical quantities, Andrei Sirenko

Click to edit the document details