1
This printout should have 27 questions.
Multiplechoice questions may continue on
the next column or page – fnd all choices
beFore answering.
001
(part 1 oF 5) 10.0 points
A car travels at a speed oF 22 m
/
s around a
curve oF radius 31 m.
The acceleration oF gravity is 9
.
8 m
/
s
2
.
2
.
9 Mg
μ
30
◦
What is the
net
centripetal Force needed to
keep the car From skidding sideways? Answer
in units oF N.
002
(part 2 oF 5) 10.0 points
Were there no Friction between the car’s tires
and the road, what centripetal Force could
be provided just by the banking oF the road?
Answer in units oF N.
003
(part 3 oF 5) 10.0 points
Now suppose the Friction Force is su±cient to
keep the car From skidding.
Calculate the
magnitude oF the normal Force exerted on the
car by the road’s surFace.
Hint:
Check the
correctness oF your answer to the frst question
beFore proceeding with this and the Following
questions. Answer in units oF N.
004
(part 4 oF 5) 10.0 points
Calculate the magnitude oF the Friction Force.
Answer in units oF N.
005
(part 5 oF 5) 10.0 points
Calculate the lowest possible value oF the
static Friction coe±cient
μ
s
that would pre
vent the car From skidding.
006
10.0 points
A 1
.
69 kg object is swung in a vertical circular
path on a string 3
.
62 m long.
The acceleration oF gravity is 9
.
8 m
/
s
2
.
IF the speed at the top oF the circle is
6
.
7 m
/
s, what is the tension in the string
when the object is at the top oF the circle?
Answer in units oF N.
007
(part 1 oF 2) 10.0 points
A small metal ball is suspended From the ceil
ing by a thread oF negligible mass. The ball
is then set in motion in a horizontal circle so
that the thread’s trajectory describes a cone.
The acceleration oF gravity is 9
.
8 m
/
s
2
.
v
r
g
ℓ
m
θ
What is the speed oF the ball when it is in
circular motion? Answer in terms oF
g
,
ℓ
and
θ
.
1.
v
=
r
g ℓ
cos
θ
2.
v
=
r
g ℓ
sin
θ
3.
v
=
r
g ℓ
sin
θ
4.
v
=
r
g ℓ
cos
θ
5.
v
=
r
g ℓ
tan
θ
6.
v
=
√
g ℓ
sin
θ
7.
v
=
√
ℓ
tan
θ
8.
v
=
g
ℓ
tan
θ
9.
v
=
r
g ℓ
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 Spring '09
 Staff
 Physics, Force, Friction, Mass, Tperiod

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