Physics 203– Final Exam
December 18, 2007
George Horton
9. A proctor will check your name sticker and your student ID sometime during the exam. Please have them ready.
10. You are not allowed to give, solicit, or receive help on the exam,
except help from a proctor. You may not change your seat without
permission from a proctor.
Your name sticker
with exam code
will help you. Also raise your hand during the exam if you have
a question.
⇒
1. The exam will last from 4:00 to 7:00 p.m. Use a #2 pencil to make
entries on the answer sheet. Enter the following id information
now, before the exam starts.
2. In the section labelled NAME (Last, First, M.I.) enter your last
name, then fill in the empty circle for a blank, then enter your
first name, another blank, and finally your middle initial.
3. Under STUDENT # enter your 9-digit Rutgers ID number.
4. Enter 203 under COURSE, and your section number under SEC.
5. Under CODE enter the exam code given above.
6. During the exam, you may use a calculator and are allowed one
handwritten 8.5” by 11” sheet of paper with notes of your choice
(both sides OK). You may not use cell phones, text messaging,
Blackberry, email, or any other electronic communication devices.
Please make sure your phone is turned off.
7. The exam consists of 30 multiple choice questions. For each multiple choice question mark only one answer on the answer sheet.
There is no deduction of points for an incorrect answer, so even if
you cannot work out the answer to a question, you should make
an educated guess.
8. Before starting the exam, make sure that your copy contains all
30 questions. Raise your hand if this is not the case, and a proctor
11. Please sign below to indicate that you have read and understood
these instructions.
12. When you are done, please hand in this cover sheet and the scantron sheet. You may keep the exam questions.
SIGNATURE:
.
o
60
1. A 10 kg mass is supported
by a massless, frictionless pulley system as shown in the
diagram. What is the tension in the string? (g = 9.8
m/s2 )
a)
b)
c)
d)
e)
98 N
49 N
8.7 N
196 N
9.8 N
10 kg
2. After a ball is thrown vertically upwards, and is in the air, its
speed
a)
b)
c)
d)
e)
increases
decreases
decreases and then increases
increases and then decreases
remains the same
3. An arctic rescue plane drops a package of supplies. It is travelling
at 40 m/s at a height of 100 m above the level ground. Neglecting
air resistance, what is the package’s speed just before impact?
a)
b)
c)
d)
e)
59.7 m/s
44.3 m/s
40.0 m/s
-59.7 m/s
84.3 m/s
4. What is the acceleration of the child in the diagram if the spring
scale reads 250 N? The boy’s weight is 320 N and the chair weighs
160 N. (Neglect friction and the mass of the string and pulley.)
a)
b)
c)
d)
e)
0.408 m/s2
2.7 m/s2
2.4 m/s2
-0.408 m/s2
-2.7 m/s2
5. A child and sled, combined mass M, slide down a frictionless slope.
If the sled starts from rest and has a speed of 3 m/s at the bottom,
what is the height of the hill?
a)
b)
c)
d)
e)
depends on the value of M
0.459 m
depends on the angle of the slope
depends on M and the angle of the slope
0.491 m
6. A 100 g glider moving at 3 cm/s on a horizontal airtrack, collides
with a 150 g glider at rest on this track and sticks to it. What
is the speed of the combined mass after the collision? (Neglect
friction)
a)
b)
c)
d)
e)
3.0
1.4
1.2
1.0
0.8
cm/s
cm/s
cm/s
cm/s
cm/s
7. A uniform, horizontal 300 N beam, 5 m long, is attached to a wall
by a pin connection that allows the beam to rotate, as shown. Its
far end is supported by a cable that makes an angle of 53◦ with
the horizontal. If a 600 N person stands 1.5 m from the wall, what
is the tension in the cable?
8. A cylinder with moment of inertia I rotates with angular velocity
ω0 about a frictionless vertical axle. A second cylinder, initially
at rest and having a moment of inertia I/2 drops on the first
cylinder, as shown in the diagram. Because of friction, both will
eventually rotate at the same angular speed, ω. What is ω?
a) you need to know I
b) you need to know the
diameters of the disks
c) 2ω0 /3
d) ω0 /2
e) ω0
9. A uniform, flat square plate, of sides 4, has a square of side 2
removed, as shown in the diagram. Where, along the x-axis is its
center of mass?
y
a)
b)
c)
d)
e)
600
388
408
300
413
N
N
N
N
N
2
a)
b)
c)
d)
e)
√
x = − √2/3
x = −2 2/3
x = 0√
x = 2/3
x = 1/2
x
4
10. Jogging along a beach you do 5×105 J of work and give off 4×104
J of heat. What is the change in your internal energy?
a)
b)
c)
d)
e)
−45 × 10 J
−54 × 104 J
−9 × 104 J
54 × 104 J
45 × 105 J
A
2A
3A
4A
5A
0.25
0.30
0.20
0.35
0.15
A
230
a) you need to know the
value of R
b) -1980 J
c) +1470 J
d) 0 J
e) +510 J
C
98
B
0.01
0.02
V (m3)
14. A certain gas is compressed adiabatically by doing 640 J of work
on it. What is the internal energy change?
12. What is the length of a simple pendulum of period 1 s?
a)
b)
c)
d)
e)
P (kPa)
5
11. A block hanging on the end of a spring at equilibrium position
x = 0. The block is now pulled down a distance A and released.
How far has it travelled between it’s release and when it passes
x = 0 on the way down?
a)
b)
c)
d)
e)
13. 0.02 moles of a monatomic ideal gas is taken through the cycle
ABC shown in the diagram. What is the change in internal energy
from C to A?
m
m
m
m
m
a)
b)
c)
d)
e)
740 J
-740 J
640 J
-640 J
depends on how many atoms per molecule
15. You see the lightening flash of a thunderstorm 15 seconds before
you hear the thunder. How far are you from the thunderstorm?
(speed of sound = 343 m/s, 1 mile = 1600 m)
a)
b)
c)
d)
e)
1
2
3
4
5
mile
miles
miles
miles
miles
16. A noisy machine in a factory produces sound with a level of 80
db. How many additional machines could you add to this factory
without exceeding the 90 db limit?
a)
b)
c)
d)
e)
none
9
8
7
10
17. A train sounds its whistle approaching a tunnel in a vertical cliff.
The whistle has a frequency of 700 Hz as heard by its engineer.
The train’s speed is 25 m/s. What is the frequency of the sound
reflected by the cliff and heard by the engineer?
a)
b)
c)
d)
e)
693
736
650
810
793
Hz
Hz
Hz
Hz
Hz
18. A 1.0 m long string, clamped at both ends, has a mass per unit
length of 2.0 × 10−3 kg/m and is under a tension of 80 N. Which
of the answers below is not a possible resonance frequency of the
string?
a)
b)
c)
d)
e)
100
250
300
400
900
Hz
Hz
Hz
Hz
Hz
19. You are a passenger in a hot-air balloon that is rising with constant velocity and you are carrying a buzzer that emits a sound
of frequency f . If you accidentally drop the buzzer from the balloon, what can you conclude about the sound you hear as it falls
towards the ground?
a)
b)
c)
d)
e)
The frequency and intensity increase
The frequency increases and the intensity decreases
The frequency decreases and the intensity increases
The frequency decreases and so does the intensity
The frequency remains the same and the intensity decreases
20. A pipe is 2.46 m long and open at both ends. Which of these
frequencies is a harmonic? (speed of sound in air: 343 m/s)
a)
b)
c)
d)
e)
215 Hz
63 Hz
100 Hz
30 Hz
209 Hz
21. Which of the following processes take place at constant temperature?
a)
b)
c)
d)
e)
adiabatic
isothermal
isobaric
reversible expansion
compression
22. A specimen of urea dissolved in water has a volume of 100 cm3
and a mass of 133 g. What is the density of the solution in kg/m3 ?
a)
b)
c)
d)
e)
1.33 × 10−3
1.33 × 102
7.54 × 103
1.33 × 103
2.66 × 103
23. A balloon, of negligible weight, is filled with helium at a density
of 0.181 kg/m3 . At this density it has a volume of 0.52 m3 . If the
filled balloon is tied to a thread and allowed to float, what is the
tension in the thread? (ρair = 1.29 kg/m3 , g = 9.8 m/s2 )
a)
b)
c)
d)
e)
none of these
0.92 N
6.57 N
4.31 N
5.65 N
24. Two light bulbs are suspended from a beam attached to identical
threads 10 cm long so that they hang about 1-2 cm apart. If you
blow through the opening between them
a)
b)
c)
d)
they move towards each other
they move away from each other
they are unaffected
initially they move away from each other and then come
together
e) they move toward the blower
27. A container holds 2.0 mol of monatomic helium gas at 20◦ C. Assuming that helium behaves like an ideal gas, what is the average kinetic energy per atom in the gas? (R = 8.314 J/(K mol),
kB = 1.381 × 10−23 J/K)
a)
b)
c)
d)
e)
249 J
3.64 × 103 J
6.07 × 10−21 J
4.2 × 10−22 J
none of the other answers
28. A sprinter is running on a level track with coefficient of friction
0.80 between her gym shoes and the track. What is the maximum
horizontal acceleration she can achieve? (g = 9.8 m/s2 )
a)
b)
c)
d)
e)
7.84 m/s2
the answer depends on the mass of the sprinter
9.8 m/s2
6.14 m/s2
8.00 m/s2
29. What is the average angular speed of the earth about the sun?
25. Pressure is
a)
b)
c)
d)
e)
J/m
Watts
Watts/Area
Force × Distance
Force/Area
26. Two spheres are made of the same metal and have the same radius,
but one is hollow and the other is solid. Air trapped in the hollow
sphere is allowed to escape through a small hole. The spheres are
taken through the same temperature increase. Which sphere’s
diameter expands more?
a)
b)
c)
d)
e)
the solid sphere’s
the hollow sphere’s
they expand the same amount
the spheres do not expand at all
insufficient information is given
a)
b)
c)
d)
e)
0.986 × 10−7 rad/s
0.896 degrees/day
4.78 × 10−6 rad/s
1.99 × 10−7 rad/s
1.986 degrees/day
30. A 10 kg block is connected to a 40 kg block as shown in the figure.
Neglect friction. A force of 50N pulls the blocks to the right. What
is the acceleration of the 10 kg block?
a)
b)
c)
d)
e)
0.5
2.0
5.0
1.0
4.0
m/s2
m/s2
m/s2
m/s2
m/s2
50 N
10 kg
40 kg