1. No category

Name: ________________________ Class: ___________________ Date: __________
ID: A
Unit Test Review
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____
1. A 60-W light bulb has a power output of 60 W, which means that it transfers energy at a rate of 60 kJ/s.
____________________
____
2. The lower the EnerGuide rating is on an appliance, the lower the savings will be compared to similar
appliances. ____________________
____
3. The number of oscillations that occur per second is the period. ____________________
____
4. When pulses overlap to create a pulse of greater amplitude, the result is referred to as constructive interference.
____________________
____
5. When pulses that are inverted with respect to each other overlap to create a pulse
of lesser amplitude, the result is constructive interference. ____________________
____
6. The speed at which sound travels through a medium depends on the stiffness of the medium. The less a medium
can be compressed, the greater the speed of sound in that medium. ____________________
____
7. The first overtone is the lowest frequency produced by a musical instrument. ____________________
____
8. As a sound source moves away from your listening position, the wavelength of sound reaching your ears
decreases. ____________________
____
9. If the listener moves towards a stationary source of sound, the pitch of the sound will appear to increase, as
heard by the listener. ____________________
____ 10. When a source moves much faster than the speed of sound, a shock wave in a(n) arc shape forms and travels
along with the source. ____________________
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 11. The energy that is stored in food is known as:
a. Elastic potential energy
b. Chemical energy
c. Thermal energy
d. Nuclear energy
1
Name: ________________________
ID: A
____ 12. In which of the following cases is the work negative?
a. A weight lifter lowers a barbell at constant velocity.
b. A vehicle experiences a breaking force while coming to rest.
c. A baseball catcher stops a fastball with her glove.
d. The work is negative in all of these situations.
____ 13. A mass is lowered at a constant speed over a height of 24.8 m. This results in a loss of 3.50 ´ 10 4 J of
gravitational potential energy. In the absence of friction, what is the force you need to exert on the mass to do
this work?
a.
b.
1.41 ´ 103 N [up]
144 N [down]
c.
d.
1.41 ´ 103 N [down]
144 N [up]
____ 14. A force of 785 N [W] is applied to a cart with a mass of 68.0 kg. The cart is rolling with an initial velocity of
12.9 m/s [W]. The force acts over a displacement of 17.5 m [W], causing the cart to accelerate to a velocity of
24.7 m/s [W]. What is the work done by the force on the cart?
a. 1.37 ´ 104 J
c. 1.03 ´ 104 J
4
b. 1.51 ´ 10 J
d. 4.75 ´ 103 J
____ 15. The two EnerGuide labels shown below are from two different kitchen appliances. The label on the left is from
a toaster, and the label on the right is from a food processor.
Which appliance would cost less to operate?
a. the toaster
b. there is not enough information given to determine which appliance costs less to operate
c. the food processor
d. both appliances have similar efficiencies
____ 16. To move forward at a constant speed of 88.0 km/h, a truck's engine generates 125 kW of power.
What is the forward force that the truck wheels are exerting on the road if its mechanical system is 21.0%
efficient?
a. 1.22 ´ 103 N
c. 1.07 ´ 103 N
3
b. 1.42 ´ 10 N
d. 1.27 ´ 103 N
2
Name: ________________________
ID: A
____ 17. Which part of a hydroelectric generating plant does not influence the quantity of electricity produced?
a. the efficiency of the turbine and generator
b. the amount of water that flows through the plant per unit time
c. the height of the dam above the surrounding land
d. the height from which the water falls
____ 18. Which of the following factors affects the amplitude of a wave in a spring?
a. the tension in the spring
c. the wavelength
b. the period
d. none of the above
Segment of a Wave
This diagram shows a segment of a wave travelling through a light spring.
____ 19. Refer to the diagram Segment of a Wave to answer this question.
The wave segment is of a wave that is moving to the right through a spring. At the instant shown, which of the
following is a correct description of the direction of motion of the spring at that point?
I. P is moving upward.
II. P is moving downward.
III. U is moving upward.
IV. U is moving downward.
a.
b.
I and III
II and III
c.
d.
II and IV
I and IV
____ 20. Which of the following statements applies/apply to the reflected pulse that is created when a pulse travelling
along an ideal spring reflects from a fixed point at the end of the spring?
I. The pulse is inverted.
II. The amplitude of the reflected pulse is less than the amplitude of the incident pulse.
a.
b.
both I and II
neither I nor II
c.
d.
3
I only
II only
Name: ________________________
ID: A
____ 21. Which of the following statements applies/apply when a pulse, travelling along an ideal spring, is reflected from
a fixed point at the end of the spring?
I. The amplitude of the reflected pulse is less than the amplitude of the incident pulse.
II. The amplitude of the reflected pulse is equal to the amplitude of the incident pulse.
III. The speed of the reflected pulse is less than the speed of the incident pulse.
IV. The speed of the reflected pulse is equal to the speed of the incident pulse.
a.
b.
I and IV
I and III
c.
d.
II and III
II and IV
____ 22. Two upright, non-identical pulses approach each other from opposite directions.
Which of the following situations represents what occurs when the pulses meet, according to the principle of
superposition?
a.
b.
IV
III
c.
d.
4
I
II
Name: ________________________
ID: A
A Standing Wave Pattern in a Spring
____ 23. Refer to the diagram A Standing Wave Pattern in a Spring to answer this question.
The number of wavelengths in the diagram is
a. 2
c. 3
b. 5
d. 4
____ 24. A violin string has a length of 33.0 cm. What is the fundamental frequency for this string if the speed of the
wave in the string is 194 m/s?
a. 392 Hz
c. 294 Hz
b. 335 Hz
d. 588 Hz
5
Name: ________________________
ID: A
Doppler Waves
When a wave source is in motion, the wavelengths in front of and behind the source are
altered.
(This diagram is not to scale.)
____ 25. Refer to the diagram Doppler Waves to answer this question.
The diagram shows the wave fronts created by a sound source moving to the right. The waves to the right of the
source (l 1 ) are 1.10 cm long, while those to the left of the source (l 2 ) are 1.52 cm long. If the speed of the
waves in the ripple tank is 4.20 cm/s, what is the actual frequency of the source?
a. 2.73 Hz
c. 2.96 Hz
b. 3.21 Hz
d. 3.82 Hz
Numeric Response
26. When a 0.350 kg mass is raised a distance of 1.20 m, the change in gravitational potential energy is ______ J.
(Record your three-digit answer on the answer sheet.)
27. A car with a mass of 1.86 ´ 103 kg increases its speed from 63.0 km/h to 90.0 km/h. The increase in kinetic
energy of the car is a.bc ´ 10d J. The values of a, b, c, and d, respectively, are ______, ______, ______, and
______. (Record all four digits of your answer on the answer sheet.)
28. A huge sled at Canada Olympic Park in Calgary has a mass of 25.0 kg. A rider with a mass of 78.0 kg begins
the run by pushing the sled to a speed of 1.20 m/s. By the time the sled gets to the first turn in the track, it has
gained 2.25 ´ 103 J of kinetic energy. At that time the speed of the sled is ______ m/s. (Record your
three-digit answer on the answer sheet.)
6
Name: ________________________
ID: A
29. A crane used to lift a 975 kg bucket of concrete operates at an efficiency of 29.8%. If the crane's motor could
generate a power of 190 kW, then the time it takes to lift the concrete to a height of 39.5 m would be ______ s.
(Record your three-digit answer on the answer sheet.)
Segment of a Wave
This diagram shows a segment of a wave travelling through a light spring.
30. Refer to the diagram Segment of a Wave to answer this question.
The wave segment shown is travelling from right to left in a spring. Identify, for the four points listed below,
the relative magnitudes of the speed of the medium, from least to greatest. Write the numbers of the points in
that order in the blanks.
1. Q
2. R
3. T
4. U
The order of the points is ______, ______, ______, ______. (Record all four digits on the answer sheet.)
31. Refer to the diagram Segment of a Wave to answer this question.
The wave segment shown is travelling from left to right in the spring. Identify, for the four points listed below,
the relative kinetic energies of the medium, from greatest to least. Write the numbers of the points in that order
in the blanks.
1. V
2. S
3. U
4. P
The order of the points is ______, ______, ______, ______. (Record all four digits on the answer sheet.)
7
Name: ________________________
ID: A
32. The diagram below represents a series of waves in a ripple tank. Identify, in order, the velocity vectors of the
waves, the wave source, the wave troughs, and the wave rays.
The order of the points is ______, ______, ______, ______. (Record all four digits on the answer sheet.)
33. A wave travels across a lake at a speed of 1.39 m/s. A cottager determines that it takes 85.0 s for 25 waves to
arrive at the shore. The wavelength of these waves is ______ m. (Record your three-digit answer on the
answer sheet.)
34. A spring is stretched to a length of 6.85 m. You generate a standing wave using a frequency of 3.50 Hz. If there
are 8 antinodes along the spring, then the speed of the wave in the spring is ______ m/s. (Record your
three-digit answer on the answer sheet.)
35. A wave in a spring, stretched to a length of 5.18 m, travels at a speed of 5.75 m/s. What frequency, in Hz, is
required to generate a standing wave pattern with six antinodes along the total length of the spring? (Record
your three-digit answer on the answer sheet.)
36. Two upright pulses travelling opposite directions overlap as they pass through the same point. If the
displacement of one pulse is twice as large as the other, and their displacement is 9 mm when they meet, the
displacement of the smaller pulse must be _____ mm. (Record your one-digit answer on the answer sheet.)
37. A clarinet is essentially a hollow tube with holes drilled in it to produce an open-pipe resonator. To create the
note called middle C, the clarinetist covers the holes along the body of the clarinet to produce a tube that is 64.1
cm long. If the speed of sound in air is 328 m/s, then the frequency of this note is ______ Hz. (Record your
three-digit answer on the answer sheet.)
38. The speed of sound in air is measured at 335 m/s. The frequency of a sound emitted by a source moving toward
you is found to be 458 Hz. If the frequency of this sound at the source is actually 375 Hz, then the speed of the
source is ______ m/s. (Record your three-digit answer on the answer sheet.)
39. The speed of sound in air is measured at 326 m/s. The frequency of a sound emitted by a source moving away
from you is found to be 288 Hz. If the frequency of this sound at the source is actually 364 Hz, then the speed
of the source is ______ m/s. (Record your three-digit answer on the answer sheet.)
8
Name: ________________________
ID: A
40. An empty theatre is measured to have a sound intensity level of 32 dB. The same theatre shows a sound
intensity level 100 000 000 times greater when measured during a rock concert. The sound intensity level at the
concert is ___ . ___ ___ ´ 10__ dB. (Record your four-digit answer on the answer sheet.)
Essay
41. Use this diagram to answer the following question.
The diagram shows a ball at rest on the top of a tall box.
Diagram is not to scale.
A ball with a mass of 1.26 kg is at rest on the top of the tall box. The ball is pushed off the tall box, bounces on
the floor, and lands on top of the lower box.
a) What is the initial gravitational potential energy of the ball relative to the floor?
b) When the ball is on top of the lower box, what is its gravitational potential energy relative to the floor?
c) What is the total change in gravitational potential energy of the ball?
d) What is the initial gravitational potential energy of the ball relative to the top of the lower box?
42. A car with a mass of 2.50 ´ 103 kg is travelling along a highway. The driver accelerates to increase the kinetic
energy of the car by 5.75 ´ 105 J. If the final speed of the car is 108 km/h, what was the speed of the car before
the driver began to accelerate?
43. An elevator at the CN Tower has a total weight of 7000 N including its occupants. Calculate the work done by
the elevator cable as the elevator descends 550 m with constant velocity.
44. Estimate the amount of work that you must do each day climbing the stairs at school. Examine the changes in
gravitational potential energy that occur each time you climb a flight of stairs.
9
Name: ________________________
ID: A
45. You and your classmates are provided with a light spring to study the motion of mechanical waves in an elastic
medium.
(a) Describe the procedure that you would use in an experiment to create short
segments of transverse and longitudinal waves in the spring. Be sure to include an
explanation of why the method you will use would create the desired wave.
(b) With the use of appropriate diagrams, indicate the parts of transverse and
longitudinal waves.
(c) Describe how you would demonstrate the relationship of the motion of the wave to
the motion of the medium at the midpoint of the spring as the wave passes that
point. For each type of wave (transverse and longitudinal), describe the
observations that you would expect to make during this experiment.
46. Two children are being pushed on swings. If they start side by side and one swings with twice the frequency of
the other, when will they be together again?
47. You generate a wave in a spring, stretched out on the floor, by oscillating your hand back and forth at a
frequency of 1.6 Hz. The wave has a 1.5-m wavelength. If the wave takes 2.9 s to travel to the other end of the
spring and back to your hand, what is the length of the stretched spring?
48. Before an orchestra plays, its instruments must be tuned so that when they play the same note, the pitch that is
produced is the same for all the instruments. Even though two perfectly in tune instruments, such as a violin
and a trumpet, play the same note, the sounds they make are distinctive and easy to distinguish from each other.
(a) When different instruments play the same note (same frequency), why do the notes
sound so different? Apply your knowledge of the physics of music in your
explanation.
(b) Different instruments use different techniques for tuning. For example, when guitar
players tune their guitars, they adjust the tension in the strings.
(i) How does tightening or loosening a string affect the frequency of the note? Make
specific reference to the relationship between fundamental frequency and the
standing wave in the string.
(ii) Use mathematical arguments from physics to demonstrate the relationships
between the variables that you included in your answer.
49. Pretend that you are a guitar player tuning your strings by listening for beats. You play a G note on the piano
and then pluck the string you want to tune to G. You first hear a few beats and as you increase the string
tension, you hear more beats. What should you do next in order to achieve a perfect match? Use the formula for
determining the beat frequency in your answer.
50. Arrange the following materials in order of how well they transmit sound, starting with the poorest and ending
with the best conductor: water, steel, dry air, fog, space, wood. Explain the reason for the order you chose.
51. During a lightning and thunder storm, an observer heard the thunder 15 s after the lightning was seen coming
towards the ground. If the air temperature at the time was 28ºC, how far was the observer from the spot the
lightning hit on the ground?
52. The sound reaching our ears from a hair dryer and a blender have about the same intensity. Yet, one of them is
much more harmful to our hearing than the other. Explain.
10
ID: A
Unit Test Review
Answer Section
MODIFIED TRUE/FALSE
1. ANS: F, 60 J/s
PTS: 1
REF: K
LOC: Phys11-SPH3U-D3.2
2. ANS: F, higher
OBJ: PhysSrc11-6.2
PTS: 1
REF: K
LOC: Phys11-SPH3U-D3.2
3. ANS: F, frequency
OBJ: PhysSrc11-6.2
PTS:
LOC:
4. ANS:
OBJ:
5. ANS:
1
REF: K
Phys11-SPH3U-E3.1
T
PhysSrc11-9.3
F, destructive
OBJ: PhysSrc11-9.2
PTS:
LOC:
6. ANS:
OBJ:
7. ANS:
1
REF: K
Phys11-SPH3U-E3.3
T
PhysSrc11-10.1
F, fundamental frequency
OBJ: PhysSrc11-9.3
PTS: 1
REF: K
LOC: Phys11-SPH3U-C3.2
8. ANS: F, increases
PTS:
LOC:
9. ANS:
OBJ:
10. ANS:
PTS: 1
REF: K
LOC: Phys11-SPH3U-E3.3
PTS: 1
REF: K
LOC: Phys11-SPH3U-C3.5
OBJ: PhysSrc11-10.2
1
REF: K
Phys11-SPH3U-C2.5
T
PhysSrc11-10.3
F, cone
OBJ: PhysSrc11-10.3
PTS: 1
REF: K
LOC: Phys11-SPH3U-C2.5
OBJ: PhysSrc11-10.3
PTS: 1
REF: K
LOC: Phys11-SPH3U-C2.5
MULTIPLE CHOICE
11. ANS:
LOC:
12. ANS:
LOC:
B
PTS: 1
Phys11-SPH3U-D3.2
D
PTS: 1
Phys11-SPH3U-D3.2
REF: K
OBJ: PhysSrc11-6.1
REF: K
OBJ: PhysSrc11-6.1
1
ID: A
13. ANS:
LOC:
14. ANS:
LOC:
15. ANS:
LOC:
16. ANS:
LOC:
17. ANS:
LOC:
18. ANS:
LOC:
19. ANS:
LOC:
20. ANS:
LOC:
21. ANS:
LOC:
22. ANS:
LOC:
23. ANS:
OBJ:
TOP:
24. ANS:
OBJ:
TOP:
25. ANS:
OBJ:
TOP:
A
PTS: 1
REF: T
OBJ:
Phys11-SPH3U-D2.3
B
PTS: 1
REF: T
OBJ:
Phys11-SPH3U-D2.3
A
PTS: 1
REF: K
OBJ:
Phys11-SPH3U-D2.5
C
PTS: 1
REF: T
OBJ:
Phys11-SPH3U-D2.5
C
PTS: 1
REF: K
OBJ:
Phys11-SPH3U-D1.2
D
PTS: 1
REF: K
OBJ:
Phys11-SPH3U-E3.1
D
PTS: 1
REF: K
OBJ:
Phys11-SPH3U-E3.1
C
PTS: 1
REF: K
OBJ:
Phys11-SPH3U-E3.1
D
PTS: 1
REF: K
OBJ:
Phys11-SPH3U-E3.1
A
PTS: 1
REF: K
OBJ:
Phys11-SPH3U-E3.4
A
PTS: 1
DIF: easy
REF:
PhysSrc11-10.2
LOC: Phys11-SPH3U-C3.2
section 8.3
KEY: standing waves | universal wave equation
C
PTS: 1
DIF: moderate
REF:
PhysSrc11-10.2
LOC: Phys11-SPH3U-C3.2
section 8.3
KEY: fundamental frequency
B
PTS: 1
DIF: moderate
REF:
PhysSrc11-10.3
LOC: Phys11-SPH3U-C2.5
section 8.4
KEY: Doppler effect | frequency
NUMERIC RESPONSE
26. ANS: 4.12
PTS: 1
REF: T
LOC: Phys11-SPH3U-D2.3
27. ANS: 2965
OBJ: PhysSrc11-6.1
PTS: 1
REF: T
LOC: Phys11-SPH3U-D2.3
28. ANS: 6.72
OBJ: PhysSrc11-6.1
PTS: 1
REF: T
LOC: Phys11-SPH3U-D2.3
OBJ: PhysSrc11-6.1
2
PhysSrc11-6.1
PhysSrc11-6.1
PhysSrc11-6.2
PhysSrc11-6.2
PhysSrc11-6.3
PhysSrc11-9.1
PhysSrc11-9.1
PhysSrc11-9.2
PhysSrc11-9.2
PhysSrc11-9.3
K
K
K
ID: A
29. ANS: 6.67
PTS: 1
REF: T
LOC: Phys11-SPH3U-D2.7
30. ANS: 2413
OBJ: PhysSrc11-6.2
PTS: 1
REF: T
LOC: Phys11-SPH3U-E3.1
31. ANS: 4231
OBJ: PhysSrc11-9.1
PTS: 1
REF: T
LOC: Phys11-SPH3U-E3.1
32. ANS: 7361
OBJ: PhysSrc11-9.1
PTS: 1
REF: T
LOC: Phys11-SPH3U-E3.1
33. ANS: 4.73
OBJ: PhysSrc11-9.1
PTS: 1
REF: T
LOC: Phys11-SPH3U-E3.1
34. ANS: 5.99
OBJ: PhysSrc11-9.2
PTS: 1
REF: T
LOC: Phys11-SPH3U-E3.4
35. ANS: 3.33
OBJ: PhysSrc11-9.3
PTS: 1
REF: T
LOC: Phys11-SPH3U-E3.4
36. ANS: 3
OBJ: PhysSrc11-9.3
PTS: 1
REF: T
LOC: Phys11-SPH3U-E3.4
37. ANS: 256
OBJ: PhysSrc11-9.3
PTS:
LOC:
KEY:
38. ANS:
1
DIF: moderate
REF: T
Phys11-SPH3U-C3.2
TOP: section 8.3
open tube | resonance | universal wave equation
60.7
OBJ: PhysSrc11-10.2
PTS: 1
DIF: moderate
LOC: Phys11-SPH3U-C2.5
39. ANS: 86.0
REF: T
TOP: section 8.3
OBJ: PhysSrc11-10.3
KEY: Doppler effect
PTS: 1
DIF: moderate
LOC: Phys11-SPH3U-C2.5
REF: T
TOP: section 8.3
OBJ: PhysSrc11-10.3
KEY: Doppler effect
3
ID: A
40. ANS: 1122
PTS: 1
REF: T
LOC: Phys11-SPH3U-C3.5
OBJ: PhysSrc11-10.1
4
ID: A
ESSAY
41. ANS:
m = 1.26 kg
h 1 = 6.85 m
h 2 = 0.750 m
g = 9.81 m/s 2
a) To find the height of the ball above the floor, add the heights of the two boxes. Use the equation for
gravitational potential energy to find the gravitational potential energy of the ball on the higher box (E p 1 )
relative to the floor.
h3 = h1 + h2
= 6.85 m + 0.750 m
= 7.60 m
E p 1 = mgh 3
çæ
m ÷ö
= æçè 1.26 kg ö÷ø çççç 9.81 2 ÷÷÷÷ (7.60 m )
s ø
è
= 93.94 J
= 93.9 J
Relative to the floor, the ball has 93.9 J of gravitational potential energy when it is on the higher box.
b) Use the equation for gravitational potential energy to find the gravitational potential energy of the ball on
the lower box (E p 2 ) relative to the floor.
E p 2 = mgh 2
æç
m ö÷
= æçè 1.26 kg ö÷ø çççç 9.81 2 ÷÷÷÷ (0.750 m )
s ø
è
= 9.270 J
= 9.27 J
Relative to the floor, the ball has 9.27 J of gravitational potential energy when it is on the lower box.
c) The change in potential energy is the difference between the two answers in parts a and b.
DE p = E p 2 - E p 1
= 9.270 J - 93.94 J
= -84.67 J
= -84.7 J
Going from the higher box to the lower box, the ball has lost 84.7 J of gravitational potential energy.
d) Relative to the top of the lower box, the initial gravitational potential energy of the ball is equal to the
negative of the change in gravitational potential energy.
E i = -DE p
= - (-84.7 J)
= 84.7 J
Relative to the top of the lower box, the ball has 84.7 J of gravitational potential energy when it is on the
higher box.
PTS: 15
REF: A
LOC: Phys11-SPH3U-D3.2
OBJ: PhysSrc11-6.1
5
ID: A
42. ANS:
75.5 km/h
PTS: 1
REF: T
LOC: Phys11-SPH3U-D2.2
43. ANS:
-3.85 ´ 106 J
OBJ: PhysSrc11-6.1
PTS: 1
REF: T
OBJ: PhysSrc11-6.1
LOC: Phys11-SPH3U-D2.2
44. ANS:
Responses will vary; students may determine this by knowing the vertical height that they climb as well as their
mass. The work done is simply the change in gravitational potential energy (mgDh) that they experience as they
ascend or descend the stairs.
PTS: 3
REF: A
LOC: Phys11-SPH3U-D2.3
OBJ: PhysSrc11-6.1
6
ID: A
45. ANS:
(a)
1. Stretch the spring along the floor between two people in the group. The straight
line the spring makes between its endpoints defines the equilibrium position of
the spring.
When you disturb the position of the spring, the elastic forces in the spring cause
each movement your hand makes to travel, in sequence, along the length of the
spring.
2. To make a transverse wave, ask the person at one end of the spring to move his
or her hand back and forth a few times, perpendicular to the equilibrium position
of the spring.
When the movement is a side-to-side oscillation, the result is a series of curved
segments on either side of the equilibrium position that move along as a train.
3.To make a longitudinal wave, ask the person at one end of the spring to move his
or her hand back and forth a few times, parallel to the equilibrium position of
the spring.
When you oscillate your hand parallel to the length of the spring, the disturbance
that moves along the spring consists of regions where the coils are stretched
farther apart, followed by a region where the coils are compressed closer
together.
(b)
To create a transverse wave, the hand oscillates perpendicular to the equilibrium position of
the spring.
7
ID: A
To create a longitudinal wave, the hand oscillates parallel to the equilibrium position of the
spring.
(c)
Attach a piece of tape (or string) to the spring near the midpoint of its length.
Observe the motion of the tape as each type of wave moves along the spring. For
each type of wave, the tape will make the same motion as the hand did when it
created the wave.
For the transverse wave, the tape will move from side to side of the equilibrium
position of the spring. After the wave has passed, the tape will return to its
original position.
For the longitudinal wave, the tape will move back and forth along the
equilibrium position of the spring. The motion of the tape will mimic the motion
of the hand that created the wave. When the wave has passed, the tape will
return to its original position.
PTS: 3
REF: A
OBJ: PhysSrc11-9.1
46. ANS:
If the ratio of frequencies is 2:1, then every time the higher frequency occurs twice, the slower frequency occurs
once. They will be together at the beginning of every swing of the slower swing, and the faster swing will have
completed two swings to every one swing of the slower swing.
PTS: 3
REF: T
OBJ: PhysSrc11-9.2
8
ID: A
47. ANS:
f = 1.6 Hz
l = 1.5 m
v = fl
v = 1.6 Hz(1.5 m)
v = 2.4
m
s
t = 2.9 s ¸ 2 = 1.45 s to travel to the end of the spring
d = vt
d = 2.4
m
(1.45 s)
s
d = 3.5 m
PTS: 3
REF: T
OBJ: PhysSrc11-9.2
48. ANS:
(a)
The note that we identify for an instrument is the fundamental frequency of the
instrument. However, each instrument also produces overtones as well as the
fundamental frequency. Since different instruments produce different combinations
of overtones, they all have distinct sounds.
(b)
(i) When a spring is stretched along a floor, the speed of a wave travelling in the
spring depends on the tension in the spring. Similarly, tightening a guitar string
causes the wave in the string to travel back and forth faster. The wavelength of the
fundamental frequency in the string is twice the length (2L) of the string. Thus,
according to the universal wave equation, the fundamental frequency produced by
the string equals the speed of the wave in the string divided by the wavelength.
v
(ii) f =
l
v
2L
From these equations, increasing the speed of the wave in a string causes a
proportional increase in the fundamental frequency, resulting in a higher note.
=
PTS: 15
DIF: moderate
REF: A
OBJ: PhysSrc11-10.2
LOC: Phys11-SPH3U-C3.2
TOP: section 8.3
KEY: universal wave equation | fundamental frequency | resonance
9
ID: A
49. ANS:
The string is in tune when there are no beats. You must decrease string tension slowly and listen as the beats
decrease in number and disappear. If two waves of equal amplitude and slightly different frequency, f1 and f2,
combine, they will produce a beat that has a frequency given by the expression:
f beat = || f 1 - f 2 ||
PTS: 3
REF: A
OBJ: PhysSrc11-10.2
LOC: Phys11-SPH3U-C3.2
50. ANS:
The correct order, from worst conductor to best, is: Space, dry air, fog, water, wood, steel. The speed of a wave
in a medium is dependent on how close together the particles of matter are in the medium, and how stiff the
medium is.
PTS: 3
REF: T
LOC: Phys11-SPH3U-E3.5
51. ANS:
v sound = 331.6 + 0.606T
OBJ: PhysSrc11-10.1
v sound = 331.6 + 0.606(28)
v sound = 348.6
m
s
Dd = vDt
Dd = 348.6
m
(15 s)
s
Dd = 5228 m = 5.2 km
PTS: 3
REF: T
OBJ: PhysSrc11-10.1
LOC: Phys11-SPH3U-E3.5
52. ANS:
Intensity is one factor that determines how harmful a device may be. Another factor is the time, how often and
for how long the device is being used. A hair dryer, being used for much longer periods of time than a blender,
is more likely to cause permanent hearing loss.
PTS: 2
REF: T
LOC: Phys11-SPH3U-E3.5
OBJ: PhysSrc11-10.1
10