November22,2006
Exam#3
Physics29L
Your Name
#
Room# -Seat
This is a closed-book
exam.Only one5"x 8" cardof notesis allowed.All your work shouldbe shown
on thesesheets.
Ifyou needmorespace,work on thebackof thepagesandindicatewherethe extra
work canbe found. You areexpectedto signthe HonorPledgebelowat theendof theexam.
Honor PledgeSignature:
u: 1.66x10-"ktt
R: 8.315J/mol.K; R: 0.0821(L.atm)/mol.K; R: 1.99cal./mol.K
Ne:6.02x1023;
G:6.67x10-llN.m2lkg2;
Score:
N1*t; g:9.8 m/s2
1 atm: 1.013x10t
Question1:
Question3:
Question4:
Question2:
B. Question:Total:
1. (20 points) A malletconsistsof a uniformcylindricalheadof mass2.0 kg anda diameter0.080m
mountedon a cylindricalhandleof mass0.50 kg and length0.24 m as shownin the figure below.
Whereis the centerof massof themallet?
2
2\
/2 cr",
L__Y.J
X,
8.00cm
kat"
t
7t mt + ?(e M*
M,
xj=
I 6 erut
lz=
o, 2& ttz
O,5oT . /ac-, + ,1.o tT. 2Yta*,
+ ?rr&
ku, = 2q'(
o, y'/trz
e*' = s .2ttF nr_
2.o
T
+ o.6,t l.t
2, (25 points) In a physicslab, a smallcubeslidesdown a frictionlessinclineas shownin the figure
below,andelasticallystrikesa cubethat is only one-hatfof its mass.If the inclineis 20 cm high and
thetableis 90 cm off the floor, wheredoeseachcubeland?
G -g."r O,-,rc =) +nqh-= 4,* vnf +
qL
1!,t1'-
vI;
rut'*',
%^n
At€.
T-r-^'.v"r'
7u" + ht2
tu2:ozt,
&*
1vrf
0 A
trtn=2r>t
o2nr.tai
*tf=
)
m, ttuL
2*t-+.t
=
Aerz + t-,
#1/a7'
arf . o, 66 o-'/s
1/? .1
tlzf
= :2,1^
crt
tt?. = lF
vo;
= A.64 *r/s
+ *z
2
3+n
3. (25 points) A 4.00kg massanda 3.00kg massareattrached
to oppositeendsof a thin 50.0cm long
horizontalrod as shown in the figure below. The systemis rotating at an angularspeedco:8.00rad/s
abouta vertical axle at the centerof the rod. Determine(a) the kinetic energyK of the system,and(b)
the angularmomentumof the system.(c) Repeatparts(a) andO) assumingthat the axle passesthough
thecentero:rn*t of the system.
(")
k = a/tJhL
t
2 = an,12+ -ar^
K=
'/rbr'-t)
ks
q,o r
v)
/-=
(.)
/-
12ts 2 =,
s (',,
= 7-
*')
( 1'05,
r2us
@rr*r)r'
! oT ) ( o,2sn)a('r,ar'/sf
= (+,0g)Ft t,o5;)(a*^1+ froru"/4
3,54.*7,
too-t s
50,oorrr.3,oU
= 24,13 *
4,OJ+?,'J
q = A4'q3e'n- = o'3/qh
fAt
2
k = /*( nr elr n&n2')ht = % ( rr.,
3 Q',ztt1e*)z+
/f,6urr
-' O.2?e'm
t"u?( o,*ro;) t o.'//r;
(/) G-t,*
= -Jr *//aa'e'-4 fl= LJr'
%-r"
z- ur
7
'tU--lqt+
2u
-
=
?(o
4
ilr=urf.t
=
(t=ur(.t
'
1l' oo't
0,10^=
0,f2q:
P,6b*/s.
2'61
k'L'F+-/r''tt
^/s
= P.2(+q-
0't1'21s7'/"ton
+
t=0'14s
U
&^ftn"e--
7J
/=fu
=
(u, rrtt
L= 3.13 b*'/
n, rr)N
= 0?,03. p-z'rr|^)' t
*fr
,,f (o,trt
x.y.odL
A
rieid bodyis made
*f9n:t"rs)
of tl
tbstened
identicar
toserher
,rn'o_t: withrength
r_,1,.J:T:T:jil"ltl*""
L (L=20cm).
":cJr
;;
i1'r'e*'r";;
fftriX
;tx*::irij:*'*:':fiil,i1
,heb.dv*n.i*.0,l;:':til{y*f,fi:fr
trr"??rt{*f#H*11#,iifl:
reangularspeedof
I
^Jrn *J L
e
&
',
t
.+ tn1 L =
J"'-
I^=lmLL
r*^u1
f znzr
G)2 e
*l
*,12
^L^+
=
?=
4
a,L+M;r/z
*S
7^t,
(10.qoints)Describ<
3:.1*, O.u.rr.on.
andexplain
,r,"Jil#
i-XE
;lfi':'"T
ef
ur'-/t
6tn
hnsr/t:
o, fu
/n
ro-(/n'nU
t= O, p
/2R
= lo,5,dl,
ZatR,
:
I
5toy,t
w,fr= \, e*_r
at
/ure
,"*OA
r'i//
t^r^
orr, B,o points
ofarorring
object
shown
inthe
a^V,,,{t.ue/,u,fi ,/
oL poi^'{ /'n d
cvfi +1,*,.
= l/, //sq4. yz^z-
4,;;,
=t
loin*
=
= T4i;i=
\l
0n
p--lL(
'/s-tz++nL2
-)
e
*Jt/^
fue
T: o, tt.2 o"*/ 2n L Rslr.cftrzt
,'t
b"/A
ro hhon
pi/h
retVe*
m h.h"n }s h)
,s
1/ = tu, r
/--
a n^d reLct"al
, //rz 7-r^I
wLt he s
Good htck and
Happy Thanksgiving!
,
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