ahn (ka6577)- Forcesof friction - ahn - (15011)
This print-out should have 10 questions.
Multiple-choice questions may continue on
thc next column or page - find all choices
beforeanswering.
s!i;f
,
001 10.0points
A block accelerates3 mf s2 down a plane inclinedat angle26.0'.
of gravity is 9.81^ls2 .
The ac-celeratiop
+e:
t'!l
\,;
jNl
-
y,
What is the frictional force acting on the
49 kg mass? Answer in units of N.
{h,^:'}l:=."Xry?
l F**.r = lYrcr1
= *t'^ls'' -.
Cl.X
, 26"
1
-_-Y_
Find p7,between the block
plane.
bhe inclined
002 10.0points
Two blocksare arrangedat the endsof a masslessstring as shownin the figure. The system
starts from rest. When the 1.47 kg masshas
fallen through 0.326m, its downwardspeedis
7 . 2 5m l s .
The accelerationof gravity is 9.8 m/s2 .
).r'19?
t€c'\
: "
i-"..)
,'l
-
t
)
tt-)
,
i 6".-.t .*
luc'
Ftl D.;
I't
r w t 6 ('.{<>
f
c"kt^- tt\{- Sc'.vu^II
t-\
\l
\
\(L
What is the frictional force between the
3.02 kg mass and the table? Answer in units
"r f,, See
,t"t ) in taxt.
003 (part 1 of 3) 10.0points
A block is at rest on the incline shown in
the figure. The cocfficientsof static and kinetic friction are Fs : 0.73 and p,p : 0.62,
respectively.
The accelerationof gravity is 9.8 m/s2 .
004 (part 2 of 3) 10.0points
What ir th"g_E$gql:lgl" which the incline
can haveso that the massdoesnot slide_4orvn
the incline? Answer in units of o. ,.
r'iLr.oix
Ti-1s
005 (part 3 of 3) 10.0points
What is the accelerationof the block down
the incline if the angle of the incline is 43' ?
fu 1',. ^ 1',. 7
Answerin units of m/s2.
'
l) cr- 16_,
006 (part 1 of 2) 10.0points
A car is traveling at 34.9mi/h on a horizontal
highway.
The accelerationof gravity is 9.8 m/s2 .
If the coefficientof friction between road
and tires on a rainy day is 0.11, what is the
minimum distancein which the car will stop?
(1
' mi : 1.609km) Answerin units of m.
Fl,r.( ,tuAer.A.L n a1u u'LU":= z..,a"t
007 (part 2 ot2) 10.0points
What is the stopping distancewhen the surfaceis dry and Fd,rs:0.655? Answer in units
of m.
10.0 points
008
A force F applied to a crate of mass M at
an angle a makes the crate move horizontally
with a constant acceleration of magnitude a.
The coefficient of kinetic friction between the
crate and the surface is p6.
ahn (ka6577) Forcesof friction - ahn - (15011)
Select the correct expressionfor llFll, tfre
magnitude of the force.
{
r.
ll;,
llfll
:-
2. ilFil:
3. ilFil:
4. ilFil:
5. ilFil:
6. ilFil:
7.
ilFil:
8.
ilFil:
9.
ilFil:
1 0 .l l F l:l
Ma-lp,kMg
p"kSrna
Ma-tpkMg
COS0 -
p/c Srn a
MalpkMg
cos a
M a - L L k Mg
cos a
p,kMg-Ma
CoSa-pkSlna
M a-
[LkM g
cos c * pl1,sin a
Ma-pkMg
COS0 - p,k Srn 0
Ma-ltrkMg
cosa*ptsina
pnMg-Ma
cosa + p7,sin a
Ma-p,nMg
p6 sin a
009 (part 1 of 2) 10.0points
Hrnt: This problem requiresa train of logic.
(1) Analyze force diagram,
(2) useNewton'sLaws, and
(3) solvethe equationsof motion.
A block starts from rest at a height of 3 m
on a fixed inclined plane.
The acceleration\f gravity is 9.8 m
\
(p
I
(..*
(-fL.
Ou.P{Jr,.a- '-:
c "^*g(a.*f c\ce-el*4t
ct
1l I
l / - t i ^ .
Vv!
010 (part 2 of 2) 10.0points
If the block continuesto slide on the ground
with the samecoefficientof friction, how far
will the block slideon the grounduntil coming
to rest? Answerin units of m.
t
5Jo-- t^*t J
irL
tom of the ramp? Answer in units of m/s.
(Ly tr r (r'P
Fi^l
I i
zo- ,At
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