This preview shows pages 1–2. Sign up to view the full content.
Physics 112 — Final Exam Solutions
Fall 2005
1.
(a)
8.0 cm
(b
)
ω
= 2
π
/T = 2
π
/(2.0 s) =
π
s
1
(c)
Q =
π
(
τ
/T) =
π
(12 s/2.0 s) = 6
π
= 19
2.
(a)
(b)
[+3 for any one of
the possible
methods for each
case, 1 for bad or
missing labels]
3.
(a)
E
(b)
B
(c)
G
(d)
C
4.
(a)
B
(b)
B
(c)
F
5.
(a)
C
(b)
D
6.
(a)
H
(b)
N [+3 for N; +1 for G, H, J, K, L, or M]
7.
G
8.
(a)
or
(b)
Σ
F
y
= f  mg = ma
y
= 0
⇒
f = mg
f
2
+ N
2
=
(mg)
2
+ N
2
= 2mg
⇒
N =
3 mg
f
≤
μ
s
N
⇒
mg
≤
μ
s
3 mg
(c)
Σ
F
x
= ma
x
⇒
N = m
v
2
R
⇒
μ
s
≥
1/
3 = 0.58
⇒
v =
NR
m
=
3 mgR
m
=
3 gR = 1.32
gR
9.
(a)
(b)
About axle:
Σ
τ
= 0 =
Mg(0.40 m)  m
p
g(0.60 m)  N(1.60 m)  Tsin60°(1.60 m) = 0
with N = mg (ball)
⇒
T =
Mg(0.40 m)  m
p
g(0.60 m)  mg(1.60 m)
(1.60 m)sin60°
=
(20 kg)(0.40 m)  (2.0 kg)(0.60 m)  (0.50 kg)(1.60 m)
(1.60 m)(0.866)
(9.8 m/s
2
) = 42.4 N
(c)
I
axle
= (20 kg)(0.40 m)
2
+
1
12
(2.0 kg)(2.00 m)
2
+ (2.0 kg)(0.60 m)
2
= 4.59 kgm
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 02/14/2008 for the course PHYS 1112 taught by Professor Leclair,a during the Spring '07 term at Cornell University (Engineering School).
 Spring '07
 LECLAIR,A
 Physics

Click to edit the document details