Download Practice_Final_B

Physics 214
Practice Final B
Fill in on the OPSCAN sheet:
1) Name
2) Student identification number
3) Exam number as 04
4) Sign the OPSCAN sheet
Important: This test consists of 30 multiple choice problems, each worth 6.667 points.
Instructions: For each problem, choose the one answer that is correct or most nearly
correct. Make a small mark, for your eyes only, near the letter of your choice. After you
finish and check all the multiple-choice problems, transfer your answers to the computer
sheet. Then, until you hand in the computer sheet, turn the sheet over and leave it face
down.
Only answers on the computer answer sheet will be graded. As your OPSCAN answer
sheet will not be returned, record the answers on the test paper that you will keep.
The correct answers will be displayed on the course web page, and you can find your score
for this exam on CHIP.
This is a closed book exam, but a crib sheet is provided. You may also use a calculator.
Any form of cheating will result in severe penalties, which will include a score of zero for
this exam and may result in a grade of F for the course and referral to the Dean of
Students.
All electronic devices must be securely put out of sight and may not be touched during the
exam.
All cell phones and pagers must be turned off.
The only items you are allowed are the exam, the opscan sheet, a pencil and a calculator
Page 1
FORMULAE AND CONSTANTS
CONVERSION FACTORS
1 inch = 2.54 cm
1 ft = 30.5 cm
1 m = 3.281 ft
1 km = 0.621 miles
1 mile = 5280 ft
1 nautical mile = 1.1508 miles
1 kg = 2.205 lbs (where g = 9.8 m/s2)
EQUATIONS
s = d/t
s = d/Δt
v = d/Δt (vector)
a = Δv/Δt (vector)
v = v0 + at
d = v0t + ½at2
d = ½(v + v0)t
F = ma (vector)
W = mg
average speed
instantaneous speed
instantaneous velocity
acceleration
force
weight
Page 2
a = v2/R
F = mv2/R
F = GM1M2/R2
W = Fd
P = W/t
KE = ½ mv2
PE = mgh
PE = ½ kx2
P = mv
FΔt = Pf – Pi = Δp
Fexternal = 0, Δp = 0
centripetal acceleration
centripetal force
gravitational force
work
power
kinetic energy
potential energy
potential energy
momentum
impulse
momentum conservation
Circumference = 2πR
g = 9.8 m/s2
G = 6.67 × 10-11N·m2/kg2
π = 3.14159
ω = θ/t = Δθ/Δt
α = Δω/t
ω = ω0t + αt
θ = ω0t + ½ αt2
Torque = Fℓ = τ
L = Iω
τ = Iα
τexternal = 0 Lf – Li = 0
circle
accn of gravity
gravitational constant
angular velocity
angular acceleration
angular momentum
torque & moment of inertia
cons of ang momentum
Page 3
P = F/A (pressure)
P = ρgh (liquid)
ρ = m/V kg/m3
PA = 1.01 x 105 Pas
Buoyant force = weight of
liquid displaced
ΔU = Q – W
PV = NkT
ε = W/QH
ε = (TH – TC)/TH
(internal energy)
(for a gas)
(engine efficiency)
(Carnot efficiency)
TC = 5/9(TF-32) TF = (9/5)TC +32 (0°C = 273.2°K)
1 calorie = 4.186 joules
Q = mcΔT c = 1 cal/gm/°C for water 0.49 cal/gm/°C for ice
Latent heat of vaporization for water = 540 cal/gm (heat
required to turn water to steam at 100 0C)
Latent heat of fusion for water = 80 cal/gm
(heat required to melt ice at 0oC)
qe = -1.6 x 10-19C
F = k q1q2/r2
k = 9 x 109N.m2/C2
E = F/q (electric field)
V = ΔPE/q (potential difference)
ΔV = Ed (uniform E)
I = q/t amps
R = ΔV/I ohms
R = R1 + R2 + R3 (series)
1/R = 1/R1+1/R2+1/R3 (parallel)
P = εI = I2R watts (power)
Page 4
MAGNETISM
F/ℓ = (2k'I1I2)/r
Parallel Wires
k' = 1 x 10-7 N/A2
F = qvBperp
Charged Particle
Φ=BA
Flux
E = ΔΦ/t
Induced EMF
ΔV2 = ΔV1(N2/N1)
Transformer
WAVES
v = fλ = λ/T
v = √F/μ
wire
vsound = 340m/s
c = 3 x 108m/s
light
nλ = dy/x
Two slit
y = λx/w
Single slit
mλ = dy/x
Grating
Page 5
NUCLEAR
4
2He – alpha decay
0
beta decay
-1e
0
position decay
1e
1. The electric potential increases between two points from 82V to 586V. What is the
magnitude of the change in potential energy when a charge of -2x10-4C is moved from
the low voltage point to the high voltage point?
A) 5.5 x 10-2
B) 9.1 x 10-2
C) 11.7 x 10-2
D) 10.1 x 10-2
E) 1.6 x 10-2
2. A current of 2.8 amps flows through a battery for 9 minutes. How much charge in
coulombs passes through the battery in that time?
A) 632
B) 856
C) 193
D) 2212
E) 1512
3. An ice cube of mass 100 g and at 0oC is dropped into a Styrofoam cup containing 400 g
of water at 25oC. The heat of fusion of ice is 80 cal/g and the specific heat capacity of
water is 1.0 cal/g C°. Assuming the cup doesn't exchange any heat, the final
temperature of the system will be which of the following?
A) +5.0oC.
B) 0oC.
C) 4oC.
D) +2.5oC.
E) -10oC.
4. Three blocks are being pulled across a frictionless horizontal floor as shown in the
diagram. What is the tension between the first and second bock in Newtons?
A)
B)
C)
D)
E)
240
500
300
150
160
Page 6
5. A football is thrown upward at an angle of 300 above the horizontal. At the highest
point, and ignoring friction, how many of the following statements are true?
The vertical acceleration is zero
The total energy of the football has not changed
There is an horizontal acceleration
The momentum of the football has not changed
The horizontal velocity has not changed
A) 3
B) 4
C) 5
D) 1
E) 2
6. A transformer has 200 turns on the primary and 20 turns on the secondary. The primary
is connected to a alternating current source of 100 millivolts. What is the voltage
induced in the secondary?
A) 1000 millivolts.
B) zero.
C) 20 millivolts.
D) 10 millivolts.
E) 4000 millivolts.
7. You have exactly 4 resistors: one 3 , one 4 , one 5 , and one 6 . How can you
combine these to make a 2 resistor? (The symbol stands for "ohm".)
A) Connect the 3 resistor in parallel with the 4 resistor.
B) Connect the 3 resistor in series with the 5 resistor.
C) Connect all four resistors in parallel with each other.
D) You can't make a 2 resistor from the ones listed.
E) Connect the 3 resistor in parallel with the 6 resistor.
8. A coil of wire has 60 turns and crossectional area = 0.02m2 forms a closed circuit with
resistance of 10ohms and has it's plane perpendicular to a magnetic field B = 1.5T. The
coil is rotated by 900 so that it's plane is parallel to the field in 0.2seconds. What is the
average current induced in the coil in amps?
A) 0.015
B) 0.21
C) 0.90
D) 0.18
E) 0.71
Page 7
9. Three equal negative charges are placed at three of the four corners of a square. What is
the direction of the electric field at the remaining corner of the square?
A) along a side of the square away from one of the charges.
B) no direction, zero field.
C) along the diagonal connecting this corner and another charge, toward the other charge.
D) along a side of the square toward one of the charges.
E) along the diagonal connecting this corner and another charge, away from the other
charge.
10. Three bulbs each 10 watts are connected in parallel as shown. One of the lights fails.
Which of the following statements is correct?
A)
B)
C)
D)
The two remaining bulbs decrease in brightness
The two remaining bulbs stay at the same brightness
The current drawn from the battery increases
The two remaining bulbs increase in brightness
11. Two suction cups each of area A = 100 centimeter squared are pressed together so that
all the air is removed. Two students try and pull them apart. What is the value of F, in
Newtons, needed to separate the cups?
A)
B)
C)
D)
E)
1.01 x 10
1.01 x 103
1.01 x 109
1.01 x 105
1.01 x 107
Page 8
12. A boat floating in a large pool is loaded with wood blocks. The water level at the pool's
edge is marked with a red line. The blocks are now thrown overboard and float outside
the boat. When the water becomes calm again which of the following statements is
true?
A) the red line is slightly lower than the water level.
B) the red line is still at the water level.
C) the red line is slightly higher than the water level.
13. A pure sample of a radioactive substance has 16x1012 atoms and the half life is 3
minutes. how long does it take until 5x1011 atoms of the substance have not yet
decayed?
A) 24 minutes
B) 96 minutes
C) 18 minutes
D) 32 minutes
E) 15 minutes
14. A piano tuner finds that the frequency of a note is 417Hz instead of 396Hz. By what
percentage should the tension in the string be changed to correct this?
A) 5%
B) 3%
C) 7%
D) 10%
E) 2%
15. The orbit of Earth about the Sun is not a circle; Earth is closer to the Sun in December
than it is in June. Thus, the speed of Earth as it moves about the Sun is
A) greater in June than it is in December.
B) steadily decreasing all year long.
C) the same all year long.
D) steadily increasing all year long.
E) greater in December than in June.
16.
A)
B)
C)
D)
E)
The atomic number of an atom is the number of
protons in the nucleus.
neutrons in the nucleus.
sum of protons and neutrons in the atom.
sum of protons and electrons in the atom.
electrons in the nucleus.
Page 9
17. A hydraulic jack is used to lift a load of weight 1000 N. The load-bearing cylinder has a
radius of 4 cm, and the other piston has a radius of 1 cm. What force must be exerted on
the smaller piston to support the load?
A) 4000 N
B) 1000 N
C) 125 N
D) 62.5 N
E) 250 N
18. An organ pipe of length 3.0 m has one end closed. The two longest possible
wavelengths for standing waves inside the pipe are
A) 12 m and 6 m.
B) 12 m and 4 m.
C) 9 m and 6 m.
D) 3 m and 1.5 m.
E) 6 m and 3 m.
19. A figure skater is spinning with her arms extended. She now pulls her arms close to her
body. Which of the following is correct?
A) Her angular momentum decreases.
B) Her moment of inertia decreases.
C) Her angular momentum increases.
D) Her kinetic energy decreases
E) Her moment of inertia increases.
20. A person weighing 500Newtons rides on a Ferris wheel sitting on a bathroom scale.At
the highest point the scale reads zero while the person continues to move in a circular
path. What is the centripetal force in Newtons?
A) 49000
B) 700
C) 51
D) 0
E) 500
Page 10
21. Light with a wavelength of 500nanometers strikes a double slit with a spacing of
0.4mm. An interference pattern is observed on a screen 2 meters away. How far from
the center of the screen in millimeters is the first bright line?
A) 30
B) 2.5
C) 1.5
D) 25
E) 5
22. Two people sit face to face on chairs which are free to roll without friction. They push
each other with a force of 50 N and move apart. Person A, whose mass (including the
chair) is 80 kg, moves to the left at 2.5 m/s. Person B, whose mass (including the chair)
is 50 kg,
A) moves to the right at 10 m/s.
B) moves to the right at 2.5 m/s.
C) moves to the right at 4 m/s.
D) moves to the right at 6m/s
E) moves to the right at 3.16 m/s.
23. A car starts from rest and travels 400m in 5.4 seconds with constant acceleration What
is the speed of the car in m/s after 5.4 seconds?
A) 156
B) 148
C) 35
D) 96
E) 74
24. A particle with a charge of 1.6x10-19C is moving with a velocity of 300m/s at 900 to a
uniform magnetic field of strength 0.5T. What is the magnitude of the force acting on
the particle in Newtons?
A) 2.4 x 10-17
B) 9.6 x 10-17
C) 9.6 x 10-19
D) 0
E) 2.4 x 10-19
Page 11
25. A household circuit rated at 120 Volts is protected by a fuse rated at 15 amps. What is
the maximum number of 100 watt light bulbs which can be lit simultaneously in parallel
in this circuit without blowing the fuse?
A) 20
B) 4
C) 8
D) 24
E) 18
26.
A)
B)
C)
D)
E)
In a nuclear reactor, “chain reaction” refers primarily to
the bonding of radioactive nuclei.
The radioactive decay of uranium
the separation of uranium-235 from uranium-238.
the production of plutonium from uranium.
the role of neutrons in the initiation and continuation of nuclear fission.
27. A string is held taut between two supports 2.0 m apart. The two longest possible
wavelengths for standing waves are:
A) 4 m and 3 m.
B) 3 m and 1.5 m.
C) 2 m and 1 m.
D) 3 m and 2 m.
E) 4 m and 2 m.
28.
A)
B)
C)
D)
E)
How much work in joules can a motor rated at 500 watts output in 10 seconds?
1000
5000
50
2000
500
29.
A)
B)
C)
D)
What is the process of nuclear fission as in a nuclear power plant?
high energy particles are released from a nucleus that is at rest.
two heavy nuclei are induced to decay simultaneously.
a nucleus is split into two less massive nuclei.
a nucleus is bombarded with another nucleus in order to induce an alpha decay.
Page 12
30. A bullet of mass 150 grams is fired into a block of mass 4kg with a velocity of 200m/s.
The bullet penetrates the wood and stops. What is the speed of the system in m/s just
after the bullet stops?
A)
B)
C)
D)
E)
10.4
9.3
7.2
5.2
7.5
Page 13
Answer Key
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
D
E
C
C
E
D
E
C
C
B
B
B
E
D
E
A
D
B
B
E
B
C
B
A
E
E
E
B
C
C
Page 14