This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 7) You are in a closed container and you have a mass and a spring hanging from the ceiling
of the container. In what way could the mass and spring be used to distinguish the
container tilting from the container accelerating horizontally? @ at rest accelerated A) If the container is accelerating, the mass and spring would hang at a different angle
relative to the container than before the container tilted. If the container is titling,
the mass and spring would remain hanging in the same direction relative to the
container as before the acceleration. @ If the container is tilting, the spring would not stretch. If the container is
accelerating horizontally, the spring will stretch. C) It is impossible to distinguish tilting from horizontal acceleration by any means. D) If the container is tilting, the mass and spring would hang at a different angle
relative to the container than before the container tilted. If the container is
accelerating horizontally, the mass and spring would remain hanging in the same
direction relative to the container as before the acceleration. E) If the container is accelerating, the spring would not stretch. If the container is titling, the spring will stretch. 8) In outer space, a large star and a small planet attract each other due to gravitational
forces. How do the magnitudes of these attractive forces compare?
A) The forces' are equal
B) The forces are zero because they cancel out
C) There are actually no forces at all
D) The small planet exerts a greater force on the large star
E) The large star exerts a greater force on the small planet page4 Physics 2A, Mechanics —— Fa112006 Instructor: B. Grinstein
Quiz # 5 INSTRUCTIONS: Fill, tear and return the bottom strip of the front page with your scantron. Keep the
top portion of the front page and the rest of the quiz. Use a pencil #2 to fill your scantron. Write your
code number and bubble it in under "EXAM NUMBER". Bubble in the quiz form (see letter AlI at
bottom of page) in your scantron under "TEST FORM" X: 4*“ 33:: V ’5" ﬁg :ﬂq
{Ur .. ,.  x: .
... H3 ‘ 5,, I .
1) A factory robot drops mputer a conveyor belt running at 9.0 / s. The 1“ x 
materials are such that as = 0.5 and p®ow far is the computer dragged before it is '1.
/Qriding smoothly on the belt? 2 #5 N 3%
/» A) 8.3 m M SQmqiﬁivfli) 14 1% ﬂow i.) C) 19 m D) 25 m '1 HA,
2) A string attached to the rearview} xiiitor of a car. A' ball is hanging on the other end of V6
. the string. The car is driving around in a circle, at a constant speed. Which of the j q following lists gives all of the forces directly acting on the ball? I It a '
_ A tension, gravity, and the eentripetal—force T _ “£31 l , $01
(:6 I ension and gravity 7' ‘3 q is.
0‘,‘ .1 C) tension and the centripetal force F \ IA 9%“ D) tension, gravity, the centripetal force, and friction f” 0Q“ 6 OK?" I do Liv E) gravity and the centripetal force \3 ’1— 5 " {it‘lli“ q %\ 9 L6 mg 71‘
$3; 3) Kieran takes off down a 50 In high, 10° slope on his jet—powered skis. The _ \
" skis have a thrust of 160 N. The combined mass of skis and Kieran is 50kg L5 L‘ (the fuel mass is negligible). Kieran‘s speed at the bottom is 40 m/ 5. What is
j the coefﬁcient of kinetic friction of his skis on snow? 4) In an amusement park ride passengers stand inside an 8 rn radius cylinder. Initially the
cylinder rotates with its axis oriented along the vertical. After the cylinder has acquired
sufﬁcient speed, it tilts into a vertical plane, that is, the axis tilts into the horizontal, as ' shown in the figure. Suppose that, once the axis has tilted into the horizontal, the ring
rotates once every 4.5 5. If a rider's mass is 74 kg, with how much force does the ring push on her at the top of the ride? [Emma 9 A/ L is HEW ? r; 7%? 2 R Inlion {:3 W N $5 .2 .. Q5 x TN 5 y is
{it SS
A)1900N B) 430N C) 730 N D) IZUON ’i‘ 5) A merrygoround is spinning with a ﬁxed angular speed. As a person is walking F : 14:;
towards the edge, ‘31
A) the force of kinetic friction must increase in order for the person not to slide off. B) the force of kinetic friction must decrease in order for the person not to slide off.
C) the force of static friction such that the person does not slide off remains the same.
D) the force of static friction must decrease in order for the person not to slide off. E) the force of static friction must increase in order for the person not to slide off. 6) Two identical boxes are sliding across the same floor at the same speed. The first box
contains a 20.0kg mass and the second box contains a 10.0—kg mass. Which box will the . . . . . .2
kinetlc friction force stop first. l: __..,l. T A) The box containing ggmg will stop first. ‘ _ or:  J‘T'~
B) Both boxes will stop at the same time. :ﬂ . I
t_ C) The box containing 10.0 kg will stop first. K: &
Wigqu U) More information is needed to answer this question. i i _ _
i l? E) The answer depends on the magnitude of the coefﬁcient of kineti ,T— HE”)
. \ ___.
12 7) Two equal—mass rocks tied to strings are whirled in horizontal circles. The radius of T it
7 .' H
circle "2" is twice that of circle "1." If the period of motion is the same for both rocks, “17:92? ‘5 what is the tension in comparedtolcord a ‘ T.‘ _ 'T‘« m Tn —"JT1 m Ta . ATM _ l1: 8) Below you see two cases: a physics student pulling or pushing a sled with a force F
which is applied at an angle 9. The physics student is unable to overcome the force of
friction. In which case is the force of friction on the sled greater? Assume the child and sled remain motionless. A) case 2 B) case 1 C) both equal D) not enough information is given to determine the answer Physics 2A, Mechanics —— Fa112006 Instructor: B. Grinstein Quiz :3 6 ,.
wow C7 INSTRUCTIONS: Fill, tear and return the bottom strip of the front page with your scantron. Keep the
top portion of the front page and the rest of the quiz. Use a pencil #2 to ﬁll your scantron. Write your
code number and bubble it in under "EXAM NUMBER". Bubble in the quiz form (see letter A—H at bottom of page) in your scantron under "TEST FORM" 1) A potential energy function for a certain system is given by U1(x) = 0:2 +
3x3. The potential energy function for a second system is given by L120?) : A + sz + 3x3, where A is a positive quantity. If an object begins at the same
initial position with the same initial velocity in both systems, how is the
motion in theth systems related?
A) The motion in the two systems will be in opposite directions. knellThe motion in the ﬁrst system will be with greater speed than in the Q1 “2 UL i w second system because of the lower potential energy. {if C) The motion in the second system will be at greater speeds in one ’4 direction and lower 5 eeds in the other direction relative to the ﬁrst
system. E A
D) The motion in the second system will be with greater Speed than in the ﬁrst system because of the greater potential energy.
he motion thetwo systems identical.“ 1 I f I
f U 2) A particle is moving in three—dimensions and is not acted on by any
_)
nonconservative forces. The particle is moving with velocity 1) when it is located at point 0. When the particle returns to point 0 at a later time, which
statement is true about its velocity? A) The magnitude of the velocity when the particle returns will be less than
_)
the magnitude of o . B) The magnitude of the velocity when the particle returns will be greater
_)
than the magnitude of v. e magnitude of the velocity when the particle returns is the magnitude
9 0ft). 0 a
D) The velocity when the particle returns will again be '0. .__._/ E) Both statements A and C are true. " corsavﬁﬁura 3} Which of the following situations requires the greatest work to be done by
the force acting on the object in the statement during the process cm: Li; 3.)
described? Remember work can be negative. N’ 1690”) VCQ' "
éfA 0.200—kg ball is picked up from rest and thrown at 20 m/s.3>
93¢ B) A 10—ton locomotive is brought to rest from a Speed of 30 m/ s... W 0 :
C) A 6.00—g raindrop falling at 40 s is stopped by the top of a person's
head. f
D) A 30—ton rock is prevented from rolling down a hill for 20 years by a
small pebble. 3‘5 l.~ el T O ‘ E) A IOOO—kg car is turns from north to west at a constant Speed of 25 m / s.
4) An object undergoes a displacement while being acted on by a constant force directed to the north. The work done on this object by the force is positive
during the displacement. Which statement is necessarily true about the
average velocity of the object during the diSplacement? A) The average velocity is toward the south. T 75
a
B) The average velocity has a component toward the south. 8 :5 @The average velocity has a component toward the north. At = D) The average velocity is toward thgﬁﬁort
E) The average velocity is zero. ,. ‘t 5) Three blocks (block P, block Q, and block R) are all initially at rest. Block P is
the most massive, and block R is the least massive. Identical horizontal forces
push each block (causing them to accelerate) for five seconds. Assuming the
coefficient of friction between the block and the ground is the same for all
blocks, which block will have the highest amount of lﬁﬁéﬁ'genergy? A} Block P —
_ a F — II. HE.
lock R t
C} Block Q P}? a? Reg;
D) They all have the same kinetic energy, although they have different
speeds. 6) A 1000.0 kg car is moving at 15 km/h. If a 2000.0 kg truck has 61 times the
kinetic energy of the car, how fast is the truck moving? A A)117km/h 19100th @3 km/h D)66km/h
F 1‘31 H: “333 ta V”— “ ii."
‘I 7) A block starts from rest at the top of a 13.00 inclined plane and encounters a ' ’1 'I’spring, of constant 4.5 kN / m, rigidly attached to the plane. If the block's
2: mass is £30 kg and it compresses the spring by 600 cm, find the distance the
(x rs 0’ block travelled before ' ncounterecl the sprin . / kw“ ‘1!" m 59.9 cm D) 561 cm
 00*: P«@‘ > A
8) A force F = 12 i 10 N acts on an object. How much work does this force
9 do as the object moves from the origin to the oint r ill13 + ‘ I g
A) 278} B) 46] !
U Néj<ﬁﬁrn03nm "51:ng
P” L D
'. ' I
I 1:“ “a! I '1 ‘f .’. . V. ’ ' M:
M v . \_ x ' _ >4
0" v ; a ;r m“’ ‘ _ :9" we . . " ‘ *
L 7, ., sz Form—G page —3 FI‘ ,i‘ l \j'l ‘1 Physics 2A, Mechanics —— Fall 2006 Instructor: B. Grinstein Quiz 1? 7 INSTRUCTIONS: Fill, tear and return the bottom strip of the front page with your scantron. Keep the
top portion of the front page and the rest of the quiz. Use a pencil #2 to fill your scantron. Write your code number and bubble it in under "EXAM NUMBER". Bubble in the quiz form (see letter A——H at
bottom of page) in your scantron under "TEST FORM" H (‘4
H‘ .—
2.0 L r , c "2
E'sA 3’s i M Meaﬁ 5
ﬂ: 1“ ‘ __ I: 53;. ab
. ‘0‘ '— "ﬁﬂ—H‘Hx W‘ A“
(in ex 1) While spinning down from 500.0 rpm to rest, a solid uniform ﬂywheel deem)
' M «‘2. work. If the radius of the disk what is its mass? 1: <50
' A) 1.7 kg B) 2.3 kg C) 2.6 kg @ 1 m
D "INl 2““ ' 12W}? $315503?) “C: ‘x
{eggs 2) A ZOOkg mass object traveling east at 20.0 m/ s collides with a 3.00—kg mass object \"‘ \ traveling west at 10.0 m/s. After the collision, the ZOO—kg mass has a velocity 5.00 m/s
\QKQD to the west. How muc kinetic energy was lost during the collision? ‘L‘
,/ W N; @4581 j) 516] C) 91.7] 13% D) 0.00] E) 175 J L 1 "3" Z n '3 \ '
[cab [(5 ZQXM) 4 al.3300 : L23 (‘5 ) (“4:4, 3 cps3 , \‘l‘ 3) A student holds a meter stick straight out with one or more masses dangling from it. Rank in order, from most difﬁcult to least difﬁcult, how hard it will be for the student to
keep the meter stick from rotating.
50 cm on ’{u‘  . \
@w’aéb “U X l {it00.003} (500(le new
)debbﬁa SO/CDQ lICLQ‘XDK—‘J ergo/om
C)b=c=d>a
E)Cbb3—d)a .9 L. e “"
.1"? 3 ‘J’ > x?
a4 ’ t
*5
J, 4) A wheel of radius R is rolling on a horizontal surface. Its center is moving forward Wltl’l
$51; speed 0. A point on the wheel a distance r/3 below the center is moving forward at a speed 20/3. The wheel is
A) slipping because its angular speed is too high to be rolling without slipping. /‘ ‘T'x ( '
2 _. @ﬂling without slipping. 2,9; v" " ' £32; air/2;}; v C slipping because its angular speed is too low to be rolling without slipping. '
"3/ ot rotating at all. \J R  39;;
Ext/3 /E)/made of rubber. I
W 5) Two objects of unequal mass are attached to opposite ends of a massless spring. At time t
l = Q  a k a = 0.00 s, the momentum of the ﬁrst object is P1 and the momentum of the second object
1.. " x" '—)
" I is P2 and the magnitude p1 2 p2. A short time later, the momentum of the first object is
—> —) — P1 and the momentum of the second object is — P2. Which statement is necessarily
true?
mhe average net external force on the system was zero during this time interval.
B) The average force of the spring on each of the two objects was zero during this time
interval.
C) The net external forCe on the system was always zero during this time interval. @he net external f: on the system was not always zero during this time interval. E) The force of the spring on each of the two objects was always zero during this time
interval. P ‘r—“mr 5' 94251120“ 4? o 6) Below are four identical figure L’s, which are constructed from two rods of equal lengths
and masses. For each figure, a different axis of rotation is indicated by the small circle
with the dot inside, which indicates an axis that is perpendicular to the plane of the Us.
The axis of rotation is located either at the center or one end of a rod for each ﬁgure. ‘__”_l
°_J°_l Rank these L ﬁgures according to their moments of inertia about the indicated axes, from
largest to smallest. ignore the width of each rod but not the length. A}IC}IA=IB>ID
5WD>1A=IB>IC
>IA=IB=ID
D)IC‘>ID>IA= 13
E) None ofthe above 7) In the figure, an L—shapecl piece is cut from a uniform sheet of metal. Which of the points
indicated is closest to the center of mass of the Lshaped object? A) 'l B) 4 page—3 8) Two objects approach each other and collide with In «ternal forces acting on either
objeca After the collision, the object with mass M has been deﬂected by 300“ from its
initial direction of travel and the other object with mass 2M has been deﬂected by 600°
from its initial direction of travel. What is the deﬂection of the direction of travel of the
center of mass of this two—body system during the collision? A) 401)" D) 45.0”
E) The deﬂection of the center of mass depends on the relative Speeds of the two
objects before the collision. page4 Physics 2A, Mechanics —— Fall 2006 Instructor: [5. Grinstein Quiz it 8 INSTRUCTIONS: Fill, tear and return the bottom strip of the front page with your scantron. Keep the
top portion of the front page and the rest of the quiz. Use a pencil #2 to fill your scantron. Write your
code number and bubble it in under “EXAM NUMBER”. Bubble in the quiz form (see letter A——H at
bottom of page) in your scantron under “TEST FORM” 1) The space station stabilizer rockets are malfunctioning, but the space station rotation rate
must be slowed down before a supply ship can dock with it. Which of the following
actions of the astronauts would slow the rotation rate of the space station? A) Start a massive flywheel spinning in a direction opposite to the direction of rotation
of the space station.
B) Move as much mass as close as possible tmvard the axis of rotation of the space station.
C) Move as much mass as far as possible away from the axis of rotation of the space station.
Dillunlaround the inside of thespace__stationina tiii‘epjion__ opposite .to_t_l_ie..ro_tation.ot' [1,. t" I, ‘. '.
the space station. N
B) More than one of the above Kw
2) A mass on a spring has an angular oscillation frequency of 2.56 rad/s. The
spring constant is 27.2 N / m, and the system’s kinetic energy is 2.76 J/ hen t = 1.56 s. Assuming that initially the system is wigs3 the oscillation l l
" l‘ \l . . . 1. '2
1 amplitude 15 closest to 93‘“ ‘ Ji (17 1‘19 8'“ (7 W ' I out
A) 68.2 cm [3) 51.4 cm C) 38.9 cm D) 59.8 cm
' 2:.SS‘s'e, _
@ "f ' " L (a _ r
Lo ; '1. \gtnl Um 61.7  1‘)
we” =,.‘+i"'l‘3 /"' /7L.gL\ ’2' .‘
( '_. / r I}, y "A ._'F_x I _ _' m“ I
if; \AgE‘S/ __,» a, I WWW—
\J = — mRMﬂT  ' \l I .\\’l’l cc
He’s5:33; —:='=‘c,r\ C  .33. ' " '_ to?“ L
r .. (5 ll\k / qr!) f Ix: i": 7
lf'l ii if
b):— itﬁa ‘9‘ Tl'z /\ x ’5 J .L
.. ’ (1“ \ I m — Joan k3 slept.”— EA _ qﬂl . h} l 90
. *1 2w o go a” »" U 1;. \_ 
\l d  QNFNﬁU] ( IL U .. ‘5‘ A L\
1:: r 
: "be L 236‘ r '
\1 t «a... 3) A ladder of weight WL leans against a wall. The ladder has rollers at the top so that the wall exerts a normal force only on the top of the ladder. A person of weight WP slowly climbs the ladder, which does not slide. A free—bod}r diagram for the ladder is shown. Fl: (fri (2 ti on] As the person ascends the ladder, the force from the wall (Fwall) A) decreases B) stays the same. C) increases D) not enough information to determine (am ( [gaff—O" :{CUr Cq {C
e—*— rr—‘hu =1) Which of following is a graph of simple periodic motion with amplitude 2.00 cm, angular frequency 2.00 5—1? B) .—" I“. I if _l. L/ﬂ‘“ Lynda : Rab
My. 5) A freely rotating turntable is rotating at 65 rad/s. lts rotational inertia about the axis of rotation is 3.5 kgmz. A non—rotating disk with rotational inertia of 1.8 kgn‘12 is dropped
onto the turntable. Friction between the disk and the turntable brings them to a common
speed. The work done against friction is closest to A) 4900 J B) 2500 J C] 4200] D) 3700 J E) 3100 J
3.5
/’H —_ H 14491 1%) S
x /l \\ m 7’ 3éxg/ﬁ‘a's ﬂ
/ b] I L” C\ l”. 1: 25 lag \ C
our '
b.— ' (9S— i/5 \ \\ L_ f: i \l : MC“ i
r l ' “a 03
/ .1 kg)
4 s v ,
2' 3 I page—3 6) l—kg rock is suspended by a massless string] from one end of a 1—m measuring stick.
What is the mass of the measuring stick it it is balanced by a support force at the 025—111 mark? _/ \ timetms
A) 0.25 kg B) 0.75 kg C) 0.5 kg D) 2 kg E) 1 kg 7) Compare the periods of two physical pendula. One is a solid disk of mass m, radius R,
supported at the edge. The other is a hoop WEISS m, radius R, supported at the edge. Disk Which has the longer period?
A) Hoop
B) Disk
C) The periods are the same.
D) Need more information to determine. 8) A particlevon—a—spring oscillates with an amplitude A, and a period T. If you double the
amplitude, the mechanical energy of the system becomes
A) twice as big.
5) 1 / 4 as big.
C) 4 times as big.
D) 1/2 as big.
E) Stays the same. page—4 a ...
View
Full Document
 Spring '07
 Hicks

Click to edit the document details