Physics II (PHY104)
Midterm II
Name
Surname
Student No
Signature
April 11th 2012
Both of the ambulance sirens emit the same tones of frequency f0. The policeman is still and the speed of
sound is c. Answer the questions 1-5 according to the below figure.
1) At what frequency does the policeman hear the siren of ambulance no.1?
a) f0
c-v1
b) f0
c
c
c) f0
c+v1
c
d) f0
c-v1
c+v1
e) f0
c
c+v1
c-v1
2) At what frequency does the policeman hear the siren of ambulance no.2?
a) f0
c-v2
b) f0
c
c
c) f0
c+v2
c
d) f0
c-v2
c+v2
e) f0
c
c+v2
c-v2
3) What is the beat frequency that, the policeman hears?
a) f0 𝑐
𝑣1 -v2
(c+v1 )(c-v2 )
b) f0 𝑐
𝑣1 +v2
(c+v1 )(c-v2 )
𝑣1 -v2
c) f0 𝑐
(c-v1 )(c+v2 )
d) f0 𝑐
𝑣1 +v2
(c-v1 )(c+v2 )
e) f0 𝑐
𝑣1 +v2
(c+v1 )(c+v2 )
4) What is the beat frequency that, the driver of ambulance no.1 hears?
a) f0
|𝑣1 -v2 |
b) f0
c-v2
|𝑣1 -v2 |
c) f0
c+v2
v2
d) f0
c+v2
v1
e) f0
c+v2
|𝑣1 -v2 |
c+v1
5) What is the beat frequency that, the driver of ambulance no.2 hears?
a) f0
|𝑣1 -v2 |
b) f0
c-v2
|𝑣1 -v2 |
c) f0
c+v1
v2
d) f0
c-v1
v2
e) f0
c+v1
|𝑣1 -v2 |
c-v1
6) What is the effective thermal conductivity coefficient of the system in the figure, if its
rigt and left surfaces are kept at different temperatures?
a)
k 1 x2 +k 2 x1
k 1 x1 +k 2 x2
b)
k 1 x1 +k 2 x2
k1k2
c)
k1k2
k 1 x1 +k 2 x2
d)
k 1 x2 −k 2 x1
k 1 x1 +k 2 x2
e)
k1k2
k 1 +k 2
7) What is the effective thermal conductivity coefficient of the system in the figure, if its rigt
and left surfaces are kept at different temperatures?
a)
k 1 k 2 |𝑘1 −𝑘2 |
k 1 +k 2
b)
k 1 +k 2
k1k2
c)
k1k2
k 1 +k 2
d)
k 1 +k 2
e)
2
|𝑘1 −𝑘2 |
2
8) What is the volume change, of a spherical object with coefficient of linear expansion of
α=10-5(1/K), when its temperature was increased by 100oC, if its volume was initially 1m3?
a) 10-5m3
b) 10-3m3
c) 2 10-3m3
d) 3 10-3m3
e) π 10-3m3
9) What is the scale pressure at 100m depth from the sea surface (ρwater=103kg/m3, g=10m/s2?)
a) 1.16Pa
b) 10.16Pa
c) 105Pa
d) 106Pa
e) 1000Pa
c) T4
d) T5
e) T-4
10) Radiant power is proportional to:
a) T2
b) T3
Answer the questions 11-15, in accordance with the figure on
the right. The container of cross sectional area A0=10m2 and
the pipes are full of with a fluid of density ρ=2 103kg/m3. The
cross sectional areas of the pipe segments are as denoted in the
figure by A1=2m2, A2=10-2m2 and A3=10-1m2. A frictionless
piston of mass M=105kg was capped over the container and
po=105Pa is the open air pressure. h0 and h3 are elevations of
the piston and the third pipe segment, relative to the axis of the
pipe segment with no.1.
11) Absolute pressure p1 in the pipe segment with no.1 is approximately is,
a) 105Pa
b) 2 105Pa
c) 3 105Pa
d) 4 105Pa
e) 5 105Pa
12) Approximate speed of the fluid at the output, that is at the third pipe segment is,
a) 1m/s
b) 5m/s
c) 10 m/s
d) 10√2 m/s
e) 100 m/s
13) Approximate speed of the fluid at the second pipe segment is;
a) 10m/s
b) 50m/s
c) 100 m/s
d) 100√2 m/s
e) 1000 m/s
d) 105Pa
e) 2 105Pa
14) What is the scale pressure at the third pipe segment?
a) -2 105Pa
b) -105Pa
c) 0
15) The piston declines approximately with speed, as it was released
a) 1m/s
b) 5m/s
c) 10 m/s
√2
d) 10 m/s
e) 0.01 m/s
d) elastic modulii
e) compressibility
16) Stress/strain defines the
a) Bulk modulus
b) Young modulus c) shear modulus
17) Third harmonic frequency of a pipe of length L=1.25m whose one end is closed is (if the speed of the
sound c=300m/s):
a) 120Hz
b) 150Hz
c) 800
d) 300Hz
e) 600Hz
c) Pascal
d) Joule
e) dimensionless
18) What is the unit of shear modulus?
a) Newton
b) Watt
19) Speed of sound in solids is given by
B
a) ρ
B
b) √ρ
Y
c) √ρ
Y
d) √B
𝑆
e) √𝐵
20) The number of antinodes for 85th harmonic of a guitar string is
a) 170
b) 84
c) 85
d) 171
e) 169