13@
;
1i t{s*ft*nf+
Slau*s
,
- somrn$n
E*ft+s.understanding
ol
bqian$*d
va.unbaran+**'t#+*u(etetes*f mnti+n)
- ld+aof i'naq-e
andinertia
-
{dead wei$1e+a tcrie
t) $peuialiaed
ferc+s
- Nerrilul
Fsrqo
- l{onmal
torie'pninelineq
Frictiqnul
ferq+.($tatisandKin+tir)
usin.g
. $) $a+i+pr*hl*rne
F,=ma,
afld
the4 mationequafiinq
,
a) Fegigpult+y
nilddynqmi{:fi
''. prohleme. Frnh{ems,
MGreadvaneqd
dynamiqs
prshlems
Li,i,
i.
Newrazu:s3 rAws
a - Hi:ni .ars,;Fv}rfisild.eela*s
r s r L,.e
| v,
of mption
.r,
.
.
t .
';'"
-L
'
-jft
T
zn" L,,u
I
2 rz.a ,
J
La.,
b - F+n"
thplet lawpf m+tipn,
phnxs*
it in c+mmpn
sffTFF
terrilF, yvhstipthstypq
pf mptien
rryhen
pnandfip*i'ir* balan+ed,
forqesaqtiing
wfrstahrutwhen
.
fan*sn
F,re
unbalanced
? tisi'i*iu-lboj
lxamptes
.
Forcesacting is zero
or balanced . ,''
Forcesactingarc Unbalanced
.
."n,
.PAGE
2
t
!t A F F
pg"ES
FXAItu{
$fl ruEWTS
ru'SS tA WS
.!
.ri
1) whenwitlyouf'*l-1.{o.t:.u onyou
'
hsideacarether
a forcerharrfuowsyJutoward
1"lts
tre
I'f,'iy;'*"Jiff
i;,!T#'lT.'r1,1:',ffi
rfi ,,'!:TJ'Jlo*s,T*l,veiocirvina
t)
fromres{dFe-Q
me.r'o
.".iip;filhdl'ti.*
oi ahecror-haiter.
T::l:H$
lrthichof rhetwois
Hf,rcer
t0stoPl"-iii5::h"
onceit isE-aveling
ateomihC
intemrsofinertia.
/-7rr
l_
-:x-"'-
Lt:
=v
3) \Yhendo yougetmuchlessgasrnileage;
h stopandgoFafiicnor on theopenhighwaygoqrgg0
o' ttlt
,
-..':ld
4
,
'
f'r , K
t
i' I
ll
"
ablockonaskinghowwouldthetensioa
of$restingbompare
to theweighr
of fheblock
traa
.*4o /crr
Jt,,rJy ! yerJ
( ! t ' o '! , ' l
%-
I
I ttr
I
l r L aI
I
I
v
Uei1r t
mph?
'
A<el,.of,n,,
up
""-r---
/
)
t ,
t
A ( E e l ( , r d lt ^ q
t'r
+..
uaJn
J
-"
rr-
oJ
fut f
t
+
, )) tt you lveresiandingon
a scelein an elevator:
Witatrrruld.the$iale'readIF -----
rt
It
J id,tJr
, n
t
r'{icr/,
o
q
t$i'
'lal
6)
A , r e.f
Dou,,
getweightless
in theelovator?
$_owdoyo_u
Howcaurhefloor bicometheceitinii--" riow canyougettwicetheweightpg)?
t
ftt
I
' 7)
Explainwhy theasfronauts
areweigfrtless
whenorbitingtheEartr?
Krt
it
,3J
ps@)
NEWTON'sz^dLAWOf FORCE
1) In wordswhot is Newton,sZndLqw-
2) whot is the eguationfor Newton'szndLow,whot doesFn"trncoh
?
3) Explainttruqrips,tion
of a tONewtonforccpushing
10Newtonforoe
onanobjectandmeetingenothec
in theoppositedircction.
*fbi
STMFLEPROBLEMS
't)
A !o Newionforccactsonul objectof masrt0 kg. Whatwill theacceleratioo
of themassbe?
'-'+
Jtrt
2) If thesarneigrceasin prcblem1 aoted
be?
ontwiceasmuchrnass
whatwouldtheacoeleration
-
nr!'
ry@'
3) In the foilovriqg siiuationsITIID - The forceon the obiect
- The objeaisaccel.
- TLe objecismass
-+o'lao'
cl= 1.5Vt
-'---
F' JazoN
1\rrc.
/
/ / / t 7r / r
4 to 6 idaoquestions
4)
hlirart'tl{e neit { crce
accelwetl ctr
ecttng
'
l*.
!r
ePldfuPl
b.
dccJbl Ef .
tha
trr' FEtr,E!nr
ofl an cbJqct
d. halvel.
lr nsnr of
douElees
the
thrccr
EI.If,F.
i..nt
l-r.r
/)
fi'7-F
Ptl
-tu
6)
1-P
JZfr
m
-7///7V-tt////ttt
Suppcce qt obJ eqt ,,i ftre.set s dacreeel
f o r c e t s . g p . p l i c d ? r r t h s o b J r e . t -I t h a
. :.
'EJ\)
" L;e.I
l|^! Farl.-e
,a
cengtEnb
i{
ni !
.
ece.et.pt iltlen
*n EhJ ect .[e Propol I ed *l31e x itretqht;f
Aie pnttr in eper
E *sc-cF. tf .thc meec a f . t h e e $ l e e t * " u g i u u . - t E G - * < i i f
ereEs€!
Er
.
g.lEdfLpl$iEr
b" doubtes'
,d, lislvE€',
Elq nqnE ef
thetg.
7)
f
Netforce F eausesmassm, to acceleraieai rate a,
A net force of 3F causes*"tt *, to ee€lErete gh
rate 2a, What j.f the rado of messi,?1to messmrP
--F
._-:e
f' \I
("t
-.-/
(l) r;3,
(2)er3
q
-
< t -
+------::€-,
')4.
.
{'.,.
\*/
)
-
L '
M UtrtrPtE
FORCE'TYPE
PRSBTEA,IS ':50
-fiN
'r""?Ll t-_t
zo&f1
((,,',1,i^-
-
fipoil
Whot is the net Forceonthe object
?
m,
-
41
.2
.
ta.*, [oi n r,ii n.er.u.iro,
Il
iJ1r.rt*b!.1h:
furcrsF1
ft
rnd Fl rcrtdE:
* rhown.'-'
Fe=8,0N
The ecceleretion
of th.bblockts
(1) 5,b rnlsEto rherieht
(g) ,l,om./s!to thele-ft.
.r
(3) 3,0 m1s!to the riEht .
(4) 3.0 m./ssro the IeFt
Whqt is the objectsqcceferotion
?
FyE
The diagram below shows a 4.0-kilogram object accelerating at 10. meters per seeondzon a rough
horizontal surface.
= 10.rnls2-+
Acceleration
Frictional
force = Ff
(Notdrawnto scale)
What is the magnitudeof the frictionalforceFoactingon the object?
(r) 5.0N
(2) I0. N
(3) 20.N
(4) 40.N
Two forces, Fi and Fn, are applied to a block on a
frictionless, h6rizontil surface as shown below.
Fa=2N
Fr=12N
surface
Frictionless
If the magnihrde of the block's accelerationis
what is the massof the
2.O.meteripersecondz,
block?
(3).6 kg
(1) I kg
(2) 5 kg
(a)7ke
A sk7divdrjlyP-Eo1t.ofe.plaae.
!fis downward
weightis 600N; He receives
a forceof air resistance.
equa[to 400N, Findtheskydiveriaccel,
.
:
'l' F
'{oau
' F ,t, r- - F t I
,
t
,
l
.
-
-
.Y
t
\ I ir)
\ '.tzr-'
'
,'roii . Go t<,,
/f':\
l
'
'
Il
,
v t/ =Coo,,v
. I
t
/
(?)
fJq
drive.itforward
A cartravelsaudthe engines
is
withaforceof 250N. Tte forceof airresisfurca
PROBTE&4S
THATf ruVSLVE
F=ma (buto=AVlt)so F=m(lVlt)
.
, fie mas_s
of e sFsceshuttlels approxirnetely
g.g I0Ekilograrns.
buripgllft.;q thenetforce
.x
.
on theshuttlels_'I.O
x 107newtotrs
U"*t.l "p.
we.rd.Whatis the speedof the shuttle10,
seiondsafterffi.o{ ftrlegle6t
air resistance
andthe
. . .rness'ehaagethe.shuttle.l
_of.
n lgl ./:
H
:.g
(s)5.0x ro.m/s
'r
fk
l'l
'l f
" . 1 x1 o t 9
' \
J
(i) s.ox losm/s
(+)s.ox ros;i;
F
aelf
,{d\
450.-hlogram womenwearinga
seatbelt
is travis
movinsi;;i-*
;;t;;ity;i
iiT':-?^:atat
meters Dersecond.In an emergency,'thE
. .rru,
Whar
F5:rllughi the to a.stopin 0.S0 seeond.,
rorce.does
seaibelf exerton the wo.man
so
ihat she remainsin her ,;;ip-
( I ) - i , 0 x r o 3N
(s) -s,0 x r0zN
(s)-S.0x tor N'
(4)-u.Ex lor N
U
7\
a)
iVl'ratareragebrakingforce ls regufmdto siop.an&$
'tocrrobileof
srlassZOOOkg
Asn a speedof g0kH&ffi
ur/s)in {.5 s? [4.2]
o
A motorcyclebeing driven on a dirt path_hits1
rock. Its-60.-kilogramcyclist is projectedov-d
into i
the handlebaxsaf 20. metersper second.
haystack.If the cyclist is brought to rest ir
0.50second,the magnihrdeof the averageforc
exertedon the cyclistby the halntackis
(3) 1.2x 103N
(r)6.0x 10rN
(4) 2.4 x I03 N
(2) 5.9 x 102N
(5)
A 0.I5-hlogrambasebdlmovingat20.metersper
secondis s-topped
by a catchgiio O.OfO
r"coid.
The averageforce stoppingthe ball is
(1 ) 3.0x 10-2N
(3) 3 .0x 1 0 1 N
(2) 3:0x 100N
(4) 3.0x 102N
A car increasesits speedfro.m
_g.6metersper
secondto I1.Z meteriper second
in 4.0seconds.
The averageaccelerati^on
of the "", Jlri"g thi,
4.0-second-interval
is
(r)0.40m/sg
(3) 2.8m/s2
(2) 2.4m/sz
(4) 5.2 mlsz
4-0.45-kilogramfootball travelingat a qpeed
-by of
22 - meters per second is caught
an
84-hlogram siationaryreceiver. If-the foLtball
comes to rest in the receiver's anns, the
6^* "F
lt,,
Fu"-" g.
ll,e
brll 6
Notewhatis Av andwhatis directionof
his acceleration
Note what is (Avlt)=(ballsacceleration)
What is the directionof the balls
accel.
4g and4g on the
. ^Baseyour answersto questions
information below.
naD
The instant before a batter hits
a
p:1f-ld",q"mbaseball,
the velocityof the
oau N 4b meters per secondwest.
The
instantafter the batter hits the ball, the
ballt
velocityis 35 metirs per second"*ri.
fnu U*t
andball are in cont"6tfor 1.0* fO-i r*";J.
48 Detennine the magnrlu-de
and directionof the
averageacceleration
of the baseballwhile iii, *
contactwith the bat. [s]
49 Calculatethe magnitudeo_fthe average
forcethe
bat exerrson the-bal_wlrilethtlrl
in contact.
lShow all work, including tfi6- "q*uon and
substitution.withunits.] tej
.-:1
Note what is (Av/t):(balls acceleration)
What is the directionof the balls accel.
(i t
/ lf-F' , u %
u o l \)t*rsry