# exam spring2010 ```SPH 4U
Holy Cross Catholic Secondary School
PHYSICS 12 (SPH 4U)
Final Exam
June 2010
Time: 2.5 hrs
Teacher: Mr. Pendergast
Total Marks: 83
30% of final mark -(24% Sections A-C , 2% Lab problem, 2% extended response, 2% STSE )
Name: ______________________________
Instructions:
This exam consists of four parts, which may be completed in any order. Below is a breakdown with a suggested time
guide.
Part A
Multiple Choice
25 marks - 40 min.
Part B
22 marks - 40 min.
Part C
Problems
36 marks - 70 min.
Total 83 marks - 150 min
*A formula sheet has been provided with the exam.
*ESL students are allowed to use a dictionary, not a translator
*There are no penalties for wrong answers. Do not leave any question blank.
*Calculators are permitted but their memories must be erased.
*Assume all data is accurate to the number of digits given and round off final answers accordingly.
*The use the following constants where appropriate.
Mass
Moon = 7.35 x 10 22 kg
Earth = 5.98 x 10 24 kg
electron = 9.11 x 10-31 kg
proton = 1.67 x 10 -27 kg
neutron = 1.68 x 10 -27 kg
sun = 1.99 x 1030 kg
Distances
Earth - Sun = 1.5 x 10 11 m
Earth’s radius = 6.37 x 10 6 m
Earth - moon = 3.82 x 10 8 m
Physical Constants
Constants
G = 6.67 x 10-11 N≅m2/kg2
uair = 4π x 10-7 T≅m/A
k = 9.0 x 109 N≅m2/C2
h = 6.626 x 10 -34 J≅s
c = 3.00 x 108 m/s
1 u = 1.661 x 10 -27 kg
1 u = 931.5 MeV/c2
Charges
electron = -1.6 x 10-19 C
proton = 1.6 x 10 -19 C
Part A Multiple Choice (25 marks)
1
Final Exam
SPH 4U June 2010
Identify the choice that best completes the statement or answers the question.
____
1. Which factor increases the force of friction acting on an object that is sliding down an incline?
a. increasing the surface area in contact
b. decreasing the surface area in contact
c. lubricating the surfaces in contact
d. increasing the angle of the incline plane
e. decreasing the angle of the incline plane
Yo-yo Diagram
A yo-yo is fully extended and is being swung clockwise in a horizontal circle on a frictionless surface. It takes
3.5 s for the yo-yo to complete one revolution. The yo-yo travels a distance of 5.3 m from point A to point C.
____
2. Use the yo-yo diagram. At the point labelled “D,” what would be the direction of the velocity vector?
a. ←
d. ↓
b. ↑
e. perpendicular to the object’s motion
c. →
____
3. Use the yo-yo diagram. What would be the direction of the acceleration vector at the point labelled “D”?
a. ←
d. ↓
b. ↑
e. perpendicular to the object’s motion
c. →
____
4. If the period of a simple harmonic motion is 2.0 s, what is the frequency?
a. zero
b. 0.5 Hz
c. 1.0 Hz
d. 1.5 Hz
e.
2.0 Hz
____
5. The name given to an electromagnetic wave (for example, X ray, radio wave) depends on the wave’s
a. colour
b. speed
c. amplitude
d. wavelength e. intensity
____
6. Monochromatic light of wavelength λ is directed through a double slit with width AB. The second dark fringe
occurs at P. What is the path difference |BP − AP|?
a. 0
b. λ
c. 1.5λ
d. 2λ
e. 2.5λ
2
Final Exam
____
SPH 4U June 2010
7. What is the gravitational force between the two masses in the system described by the data below?
System
1
2
Mass 1 (kg)
1
2
Mass 2 (kg)
2
4
Separation distance (m)
2
1
Gravitational force (N)
F
?
2
a.
F
b.
8F
c.
16F
d.
32F
e.
64F
____
8. A puck hits a wall at 2.0 m/s[E] and rebounds. If the collision is elastic, which of the following will undergo a
change?
a. speed
b. kinetic
c. gravitational d. momentum e. mass
energy
potential
energy
____
9. Which of the following has the greatest momentum?
a. a hockey puck flying past a goalie into the net
b. a cat running after a mouse
d. a transport truck moving at 100 km/h on a highway
e. the Moon in its orbit around Earth
____ 10. Suppose a cannon is designed in such a way that the cannon ball is heavier than the cannon. Which of the
following is a false statement about what happens when the cannon fires?
a. The law of conservation of momentum applies.
b. The sum of the momenta is zero.
c. The cannon recoils at a speed faster than the cannon ball shoots out.
d. The law of conservation of momentum does not apply.
e. The law of conservation of energy applies.
____ 11. Which field(s) does a moving charged particle generate?
a. magnetic field
d. magnetic field and electric field
b. gravitational field
e. electric field and gravitational field
c. electric field
____ 12. Which scientist first proposed matter waves?
a. Albert Einstein
b. Max Planck
c.
Heinrich Hertz
d.
Louis de Broglie
____ 13. Which object is an inertial frame of reference?
a. a merry-go-round
b. a car gaining or losing speed
c. a car at rest
d. a car rounding a curve at constant speed
e. either a car at rest or a car rounding a curve at constant speed
____ 14. As seen by an observer at rest, which quantity of a body is smaller when the body is moving at a relativistic
speed than when the body is moving at a non-relativistic speed?
a. elapsed time between two on-board
d. momentum
events
b. mass
e. kinetic energy
c. length
3
Final Exam
SPH 4U June 2010
____ 15. In a completely dark room, what does a body at a temperature of 20°C emit?
d. mainly infrared radiation and ultraviolet
e. depends on the colour of the body
____ 16. How can an electron in an atom emit a photon?
a. by remaining at its energy level
b. by “falling” to a lower energy level
c. by “rising” to a higher energy level
d. by wave particle duality
e. by reduction of its wave function
____ 17. Which element has the greatest binding energy per nucleon?
a. carbon
b. iron
c. hydrogen
d. helium
e.
uranium
____ 18. In a chain reaction involving uranium, which type of particle enters and destabilizes uranium nuclei?
a. a proton
d. an alpha particle
b. a neutron
e. a beta particle
c. an electron
____ 19. How much of a radioactive substance remains after three half-lives?
a. one half
b. one third
c. one quarter d. one sixth
____ 20. An object can not have a charge of
a. 3.2 x 10–19C
b. 4.5 x 10–19C
c.
d.
e.
one eighth
8.0 x 10–19 C
9.6 x 10–19 C
____ 21. A baseball is thrown vertically into the air. The instantaneous acceleration of the aball at the highest point in
its travel is
a. 9.8 m/s2 up
b. 9.8 m/s2 down
c. changing from 9.8 m/s2 down to 9.8 m/s2 up
d. changing from 9.8 m/s2 up to 9.8 m/s2 down
e. zero
____ 22. You throw a rock straight up into the air. While it falls, its total energy
a. remains constant
c. decreases then increases
d. increases then decreases
4
Final Exam
SPH 4U June 2010
____ 23. 26. A free electron and a free proton are placed between two oppositely charged parallel plates. Both are
closer to the positive plate than the negative plate. See diagram to the right. Which of the following
statements is true?
I. The force on the proton is greater than the force on the electron.
II. The potential energy of the proton is greater than that of the electron.
III. The potential energy of the proton and the electron is the same.
a.
b.
c.
I only
II only
III only D
d.
e.
I & II only
I & III only
____ 24. Two cars approach each other, each at speed v. The driver of car A turns on its headlights. The driver of car B
sees the light (the leading edge of the photons, not the headlight image) approaching. At what speed is the
light approaching?
a. v
b. c
c. v + c
d. 2v
____ 25. Diffraction refers to
a. the bending of a wave around a corner
b. the monochromatic nature of light
c. the separation of white light into the visible spectrum
d. the bending of light when it changes mediums
5
Final Exam
SPH 4U June 2010
Part B Short Answer (22 marks)
1. Given the following velocity- time graph, determine
i) when the object was stopped (1marks)
ii) the acceleration of the object at 6.0 s (1 marks)
iii) the displacement from 0-5 s (1 marks)
2. Red light of wavelength 620 nm is shining through a double slit of 1.20 x 10 -4 m. Determine the distance
between the first and fourth nodal lines if the screen is 24 m away.
(2 marks)
3. Determine the magnetic field strenth of a long coil of length 15 cm which has 400 turns if it draws a 12 A
current.
(2 marks)
4. What is the energy of an electron in Bohr’s hydrogen atom if it is the 3rd orbital?
(2 marks)
5. Radioactive iodine - 128 has a half-life of 25 min, is sometimes used to treat thyroid problems. If 40 mg of
iodine 128 is injected into a patient, how much will remain after 100 min.
(2marks)
6
Final Exam
SPH 4U June 2010
6. A 5.0 kg cart is pulled from rest along a straight line with the horizontal force shown in the graph. Find the
kinetic energy of the cart at 4.0 m. (2 marks)
7. List 4 examples of electromagnetic radiation placing them in order from lowest frequency to highest
frequency. (2marks)
____________
_____________
_____________
____________
8. Write the equation for each reaction.
a) carbon-10 (106 C) decayed by positron emission
Au) decayed by beta minus emission
b) gold-198 (198
79
Ra) decayed by alpha emission
88
(3 marks)
9. An electron is moving at 0.995c, parallel to a metre stick. How long is the metre stick in the electron’s frame
of reference?
(2 marks)
10. A physics student has a mass of 78 kg. The mass of a physics textbook is 1.4 kg. Determine the force of
gravitational attraction between the student and the textbook if there is 1.2 m between their centres.
(2 marks)
7
Final Exam
SPH 4U June 2010
Part C Problems ( 36 marks) - answer any 6 of the following 7 questions
1. A 2.9 × 10−13 kg latex sphere (balloon) is moving up, at a constant velocity of 0.013 mm/s, between two large
horizontally plates. The plates are 1.500 cm apart, with a potential difference of 3.00 × 102 V between them.
How many extra electrons does the sphere have? (6 marks)
2. Three charges sit on the vertices of triangle with side lengths of 5 cm, 5 cm and 10 cm. The interior angles of
the triangle are 25o, 25o, 130o. If charge A is 6 uC, charge B is 7 uC, and charge C is 9 uC,
a) determine the force exerted on charge C by charge A. ( 2 marks)
b) determine the net force on charge A. (4 marks)
3. The work function of a particular metal is 3.2 eV. If a photon of wavelength 270 nm hits the plate then
a) what is the energy of the emitted electron? (4 marks)
b) what is the velocity of this electron? (2 marks)
4. A 420 kg satellite is launched into a circular orbit and attains an orbital altitude of 950 km above the Earth’s
surface. (6 marks)
a) Determine the satellite’s orbital velocity.
b) Determine the satellite’s total energy.
5. If the collision of the cars is ellastic, determine their velocities after the collision. (6 marks)
6. A projectile is 2.6 m above the ground and is launched with a horizontal velocity of 12 m/s. How far
horizontally does the projectile travel? (6 marks)
7. Eric and Josh decide to retry the friction lab. This time, their procedure will consist of letting an object slide
up an incline plane and they will measure the distant travelled until the objects stops, assuming that the
frictional force is constant during its entire trip up the plane. Their data consists of a 2.0 kg wooden block
with an iniatial velocity of 3 m/s sliding up an incline plane, inclined at 30 o to the horizontal, a distance of 47
cm. Determine the object’s coefficient of friction. Include a freebody diagram. (6 marks)
8
Final Exam
SPH 4U June 2010
Part D Lab Question (12 marks)
1. The following data was collected from our conservation of momentum in two dimensions lab.
Observations (scale 1cm = 6cm)
Questions
1. Construct a table of the results indicating an appropriate uncertainty. (4 marks)
2. Mathematically, analyze the data to determine if momentum was conserved. (4 marks)
9
Final Exam
SPH 4U June 2010
3. Discuss the precision and accuracy of your results. (4 marks)
10
ID: A
SPH 4U
MULTIPLE CHOICE
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.
ANS:
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ANS:
E
B
C
B
D
D
E
D
E
D
D
D
C
C
B
B
B
B
E
B
B
A
B
B
A
PTS:
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1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
DIF:
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DIF:
difficult
easy
average
easy
easy
easy
difficult
average
easy
difficult
easy
easy
easy
average
easy
average
easy
easy
average
DIF: easy
1. ANS:
d
PTS: 1
2. ANS:
f
PTS: 1
3. ANS:
f
PTS: 1
1
REF:
REF:
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REF:
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
MC
K/U
K/U
K/U
K/U
K/U
MC
REF: K/U
ID: A
4. ANS:
d
PTS: 1
5. ANS:
f
PTS: 1
6. ANS:
f
PTS: 1
7. ANS:
d
PTS: 1
8. ANS:
a) 106 C → −10 e + 105 B
b)
c)
198
79
223
88
Au → −10 e + 198
Hg
80
Ra → 42 He + 219
Rn
86
PTS: 1
9. ANS:
L0
L=
DIF: average
REF: K/U
γ
100 cm
=
10.0
= 10 cm
PTS: 1
DIF: easy
REF: K/U
10. ANS:
m1 m2
Fg = G 2
r
ÁÊÁ
N • m2 ˜ˆ˜˜ (78 kg)(1.4 kg)
˜
= ÁÁÁÁ 6.67 × 10 −11
2
kg2 ˜˜˜
ÁË
(1.2 m)
¯
= 5.06 × 10−9 N
PTS: 1
DIF: easy
REF: K/U
2
ID: A
PROBLEM
1. ANS:
FQ = Fg
ä
E q = mg
Q
q=
mg
ä
E
Q
mg
ΔV
Δd
(2.90 × 10−13 kg)(9.81 N/kg)
=
ÁÊÁ 3.00 × 10 2 V ˜ˆ˜
ÁÁ
˜
ÁÁ 1.50 × 10 −2 m ˜˜˜
Á
˜
Ë
¯
−16
= 1.42 × 10 N • m/V
= 1.42 × 10−16 C
1.42 × 10 −16 C
e number =
1.602 × 10 −19 C/electron
= 8.88 × 10 2 electrons
q=
PTS: 1
2. ANS:
v
DIF: average
REF: K/U
PTS: 1
3. ANS:
v
PTS: 1
4. ANS:
none
PTS: 1
5. ANS:
v
PTS: 1
3
ID: A
6. ANS:
Consider the vertical components of the projectile.
vvi = 0, ag = 9.81 m/s2, dv = 2.6 m, t = ?
1
dv = vvit + at2
2
2d
t2 =
ag
2 (2.6 m)
9.81 m/s 2
= 0.53
t = 0.73 s
Consider the horizontal components of the projectile.
t = 0.73 s, vh = 12 m/s, dh = ?
dh = vh(t)
= (12 m/s)(0.73 s)
= 8.8 m
=
PTS: 1
7. ANS:
c
DIF: average
REF: K/U
PTS: 1
OTHER
1. ANS:
k
PTS: 1
4
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