'
I
I
I
v
ptraffifrCIe
prCIhfiem
Nnffinon
Effiro
BLOCK_
Conve|rionProblemg
1. 2 5 0 c m t o m
4-@un"lrn
rcEln
. e.€ rn
2. 4 i n t o c m
4nx2.4ctn
. to.t@c-n
lin
3. 50 kmto mi
b t q flr
tffi_tM'
31'cB m;
t)41n t&m'
4. 48 h to min
46h'@n=
111
28rr€f)mrl
5 .4S i ntom
l$6'4cm,
I in
6. 35 m/sto mi/h
t#,ffi*,ffi
!4.
t@crn -
l'2241
+783m'/r1
''#':k;tr=24n;/^
L Duringan Apollomoonlanding,reflectingpanelswere placedon the
moon.ThisallowedEarth-based
astronomers
to shootlaserbeamsat the
moon'ssurfaceto determineits distance.The reflectedlaserbeamwas
observed
2.52s afterthe laserpulsewassent. lf thespeedof lightis
300,000,000
m/s,whatwasthedistance
betweenthe astronomers
and
the moon? (Hintl Thereis a bitof a trickin thisonel)
a I ' a [email protected]
L - l.\tos
\. #to..J(].-,6x)
mls
d - vt
, (rcup,,@r:'9{I.zb=)
= 37A@,rcrY1
Answer:
3-F @,
f) fyr ae 3-78xt&rn
L The peregrinefalconis the world'sfastestknownbird and has been
clockeddivingdownwardtowardits preywith a constantverticalvelocity
of 97.2m/s. lf thefalcondivesstraight
downfroma heightof100m, how
muchtimedoesthisgivea rabbitbelowto considerhisnextmoveas the
falconbeginshisdescent?
V' q7.2rfl9
cl- t@ rn
d
l@rn
q-7.2m15
r-o3s
Answer:
1.o33
10.TheKentuckyDerby,the firstof threehorseracesfor the triplecrown,was
wonon May7, 2000by Fusaichi
Pegasus
witha timeof 121.1s. lf the
racecovers2011.25m, whatwas FusaichiPegasus'averagespeedin a)
/
m/s?b)mi/h?
V- I
. ?Dll.?Flln
-IZI'T5-
d" 2Plt.zsrn
= 11". 6t rn/ S
rto.bfm
-rs
\
L
L't.zls
^A-
R
lmi - 3(&s
^ @rn" -i-E
Answer:
a llr.Ll
fnrg
ensuer:
a....,!f1!12\/
h --
11.Foryears,the postedhighwayspeedlimitwas 88.5km/h(55 mi/h)but
now someruralstretchesof highwayhavepostedspeedlimitsof 104.6
km/h(65 mi/h). In Maine,the distancefrom Portlandto Bangoris 215 km.
Howmuchtime can be savedin travelingfrom Portlandto Bangorat this
higherspeedlimit?
,".dm&
d' 2t5 K(n
t= g
t' d
-2'F-Krn.
g.5Kftvn
'2.+3h
Answer:
-z'SWf\
@td .bvrqn
' 2.o6h
2.4& 2.06=.37h
12.Atortoiseand a hareare in a roadraceto defendthe honorof their
breeds.The tortoisecrawlsthe entire1000m distanceat a speedof
.2000m/swhilethe rabbitrunsthefirst200 m at 2.OO
m/s. Therabbit
then stopsto take a napfor 1.3h and awakensto finishthe last 8OOm
with an averagespeedof 3.00m/s. Who wins the raceand bv howmuch
time?
lare'
f,*r
Aar+t'
ffi 'd=2@n
F rt2 :
t= l 3 l 1
"
-lorlotse."
v= 2ml9
+\-= 4!F
d- ( CO r n
v:. z c f , lC m r s
+=
F t 3l
d "@ ft1
y= 3.@ n1l5
t.3hrw,
1.
'
2 MLS
= 267s
4(&3
r@ s+ LlGSOsI 2fo1s '-
= l@ 3
A
I
" tcCorh
5a17 3
-z ml9
= wx) 5
@rn
?'r1ls
Answer:W'bs€
bt
4-l s
13.Two physicsprofessorschallengeeachotherto a 100m raceacrossthe
footballfield.
The loserwillgradethewinner'sphysicslabsfor onemonth.
Dr.Nelsonrunsthe racein 10.40s. Dr.Brayrunsthefirst25.0m withan
averagespeedof '10.0m/s,the next50.0m with an averagespeedof 9.50
m/s,andthe last25.0m withan averagespeedof 11.1m/s. a) Whogets
stuckgradingphysicslabsfor the nextmonth? b) How closewas the p
Dr'Nascn'
l6 . - t S
.'""t'v- furg"
lo' d-2srn
V * tOrnlS
t's
'29r^
tom'5
2d: d-*,rn
v=g.sm6
)-@r
'?a'l s
\
3'd :
'5'zb3
d-zsrn
y=1. I rnls
=- ?.<s .
+ = ZS|A
L il.-i_m1s
Answer:a.
Answer:b.
R
----1
2.5s*
2.25 3
5.2La5+ Z 7 5 5 =
to.ol5
14.Acaterpillarcrawlingup a leafslowsfrom .75 cm/slo .50 cm/sat a rateof
-.05cm/s'. Howlongdoesit takethe caterpillar
to makethechange?
/
% ' .75c-ls
Vf=
t'u?'
SO cmls
5e crn/s- .7scrnls
.-. o5 cm/sz-
a=- . oscm/s'
Answer: 5
=F\-
-s
15.1nthe Wizardof Oz, Dorothyawakensin lvlunchkinland
whereher house
hasbeenblownby a tornado.lf the housefellfroma heightof 3000m,
withwhatsDeeddid it hit the WickedWitchof the Eastwhenit landed?
g)= prYl
Vq"^'[yp,$
9 = q.8 ^ ls'
'm:;t
y :6 ml S
'Y=e,s64-"
= Zqzmls
Answer;Jz+2
Ffl LS
Indonesia
hasbeen
16.TheTamboravolcanoon the islandof Sumbawa,
knownto throwash intothe air with a speedof 625 m/sduringan
plumehaverisen?b) on
eruption.a) Howhighcouldthisvolcanic
gravity
dueto
is lessthanon Earth,would
Venus,wherethe acceleration
thisvolcanicplumerisehigheror notas highas it doeson Earth?
Vo' - G,75m15
V 4. O m 1 5
mls'
9' 9'8
d=
vf t-vo'
2D
,,s,
z(q. t mls)
= -[g,QT
- 19.93(> rfl 6up)
ens*er:
rn
i+ walld @
hlgrw
'17.
ChiefBoolie,thejungledweller,
is out huntingfor dinnerwhena coconut
fallsfromatreeand landson histoe. lfthe nutfellforl.4s,howfastwas
it traveling
whenit hitChiefBoolie's
toe?
Yo=OmlS
t = l '4s
vr' Vr S
= omls + Cqg,.nlseXr.4s)
g,q . 6\ E ^ L
= \b.12 ml1
nnswer:
13.72 mlS
18.Hereis a betthatyouarealmostsureto winI Trydropping
a dollarbi..
througha friend'sfingersand offerto let her keep it if she can catchit.
justat thefingerlevelandyourfriendshould
The billshouldbe started
haveanyadvanced
warningwhenit is goingto drop. A dollarbillhasa
lengthof 15.5cm and humanreaction
timeis rarelylessthan.20s. Do
the necessarvcalculations
whv
is
this almosta surebet?
-
t ---z o s
a)a
-J
q.8mls'
o n 'l s
d= Vrt + tlzglz
- rl7(q.s"'s)(zosT
?orn - zoct{)
nns*er: k2ill woJld Fr.rue1o ce 2ocrn
long
19.On July31, 1994,SergeiBubkaof the Ukrainebrokehisownworldpolevaultingrecordby attaining
a heightof 6.14m. Howlongdid it takeBubka
ground
to returnto the
fromthehighestpartof hisvault?
d= 6 .l 4 r n
V =o-l s
Q'9.Bmlsz
nnswer:
l. lt.5
t = ^fEtg
%1[n\
'1(fi 3 u - l 'l l s
20.AChristmas
treeballwillbreakif droooedon a hardwood
floorwitha
speedof 2.0 m/sor more.Hollyis decorating
herChristmas
treewhen
hercat,Trickor,tapsa ball,causingit to fall 15 cm froma treebranchto
thefloor. Doesthe ballbreak?
I
V = o m ls
.15fn
6 - rsc*, J-ro-o".^-
\'1"2+Zfi
"T
"lo*zrqEi665rn)
q-e.gnlsL
2g{r""ly
Answer; r\ L,
21.Perhapssometimein thefuture,NASAwilldevelopa program
to landa
humanbeingon Mars.lf youwerethefirstMarsexplorer
anddiscovered
thatwhenyou droppeda hammerit took.68s to fall.90m to theground,
whatwouldyou calculate
forthegravitational
acceleration
on Mars?
e-+
t-, .togS
d ''9 o r n
answer:3.N
rYll}z
- i.@n/5,2-
22.Sethis doinghisstudentdriving
withthe "Give-lvle-A-Brake"
drivingschool
and is travelingdownthe interstatewith a speedof 9.0 m/s. Mackis
drivinghis"18wheeler"
downthefastlaneat27.0 m/swhenhe notices
Seth30.0m aheadof himin the rightlane. a) lf MackandSethmaintain
theirspeeds,howfar mustMacktravelbeforehe catchesup with Seth?
b) Howlongwillthistake?
Hint! Only do this one if you really want a challenge!
a. t-*
=(dtrmrn)Vn so dsVm=(ds+arn)vs
"&
rnts)
tzz. o *ls)' (ds +3o1..,)6Q
=
516 = l5rn -[ 3om 45rn
en"*"., 45 hO
".
Answer:
b.
1.7.5
b't'
d
=45n
Znnls
= l. 1S