Grade 12 Prototype Examination
Physics 30
Course Code 8257
Barcode Number
Month Day
Physics
Time: Two and One-Half Hours
Calculators may be used. Only silent hand-held calculators designed for mathematical computations such as logarithmic, trigonometric, and graphing functions are permissible. Computers, calculators with QWERTY keyboards, calculators capable of symbolic manipulation, and electronic writing pads are not allowed. Calculators that have built-in notes (definitions or explanations in alpha notation) that cannot be cleared are not permitted. All calculators must be cleared of programs.
Do not spend too much time on any question. Read the questions carefully.
The examination consists of 45 multiple-choice and 5 numeric response questions of equal value which will be machine scored. Record your answers on the Student Examination Form which is provided. Each multiple choice question has four suggested answers, one of which is better than the others. Select the best answer and record it on the Student Examination Form as shown in the example below:
Student Examination Form:
Multiple Choice
Which subject is this examination being written in?
A. Foundations of Mathematics B. Physics
C. Pre-Calculus
D. Workplace and Apprenticeship Mathematics
1. A B C D
Numeric Response
Calculation Questions and Solutions
What is the distance travelled by a car moving at 10 m/s for 20 seconds?
All numeric response questions have a solution between 0 and 9999. If your solution is not a whole number (e.g. a decimal number), round your answer to the nearest whole number. For questions that involved rounding during calculations or the interpretation of graphs, the solution will include an acceptable range.
Use an ordinary HB pencil to mark your answers on the Student Examination Form. If you change your mind about an answer, be sure to erase the first mark completely. There should be only one answer marked for each question. Be sure there are no stray pencil marks on your answer sheet. If you need space for rough work, use the space in the examination booklet beside each question.
Physics 30 Reference Material
These metric (SI) units and symbol may be used throughout this test.
Unit Symbol Quantity Unit Symbol Quantity coulomb
hertz joule kilogram metre
C Hz J kg m
electric charge frequency work, energy mass
length
newton second watt electron volt
N s W eV
force time power energy
Quantities that may be needed for calculations
Name Symbol Value
acceleration due to gravity at
Earth’s surface (approx..) g 9.81m/s2
Coulomb’s constant k 8.99 10 N· m 9 2/C2
electron volt eV 1 eV 1.60 10 19J
elementary charge e 1.60 10 19C
gravitational constant G 6.67 10 11N · m /kg2 2
Planck’s constant h 6.63 10 34 J s·
15
4.14 10 eV s· speed of light (in a vacuum) c 3.00 10 m/s 8
Conventions used for expressing direction in Vector Quantities Example:
The direction of vector A can be expressed as: [E 30 N] or [N 60 E]
Physics Formulas
Modern Physics
2
E mc Ehf E c
h
Forces and Motion
2 2 2
c a b c2a2b22ab cos C sin A sin B sin C
a b c
2
i 1
d v t a t 2
d 1(vi v ) tf 2
2 2
f i
v v 2a d
f i
v v a t v d t v a t
F ma Fg mg
2 r v
T
a 4 r22 T
a v2
r
v gr F 4 mr22 T
F mv2
r Conservation Laws 2 k 1 E mv 2
Epmgh ETEkEp
W E W F d W F d cos
1 2 p
Gm m E
r
1 2
p
q q E
r
k mv
F t m v m v1 1m v2 2 m v1 1' m v2 2' '
1 1 2 2 1 2
m v m v (m m )v
% out
in E efficiency 100 E Fields 1 2 2 Gm m F r
Periodic Table of Elements
1 18
1 H Hydrogen
1.01 2 13 14 15 16 17
2 He Helium 4.00
11 Atomic Number Na Atomic Symbol
Sodium Element name
22.99 Average Atomic mass
( ) Indicates mass of the most stable isotope
3 Li Lithium 6.94 4 Be Beryllium 9.01 5 B Boron 10.81 6 C Carbon 12.01 7 N Nitrogen 14.01 8 O Oxygen 16.00 9 F Fluorine 19.00 10 Ne Neon 20.18 11 Na Sodium 22.99 12 Mg Magnesium
24.31 3 4 5 6 7 8 9 10 11 12
13 Al Aluminum 26.98 14 Si Silicon 28.09 15 P Phosphorus 30.97 16 S Sulfur 32.07 17 Cl Chlorine 35.45 18 Ar Argon 39.95 19 K Potassium 39.10 20 Ca Calcium 40.08 21 Sc Scandium 44.96 22 Ti Titanium 47.87 23 V Vanadium 50.94 24 Cr Chromium 52.00 25 Mn Manganese 54.94 26 Fe Iron 55.85 27 Co Cobalt 58.93 28 Ni Nickel 58.69 29 Cu Copper 63.55 30 Zn Zinc 65.41 31 Ga Gallium 69.72 32 Ge Germanium 72.64 33 As Arsenic 74.92 34 Se Selenium 78.96 35 Br Bromine 79.90 36 Kr Krypton 83.80 37 Rb Rubidium 85.47 38 Sr Strontium 87.62 39 Y Yttrium 88.91 40 Zr Zirconium 91.22 41 Nb Niobium 92.91 42 Mo Molybdenum 95.94 43 Tc Technetium (98) 44 Ru Ruthenium 101.07 45 Rh Rhodium 102.91 46 Pd Palladium 106.42 47 Ag Silver 107.87 48 Cd Cadmium 112.41 49 In Indium 114.82 50 Sn Tin 118.71 51 Sb Antimony 121.76 52 Te Tellurium 127.60 53 I Iodine 126.90 54 Xe Xenon 131.29 55 Cs Cesium 132.91 56 Ba Barium 137.33 57-70 * 71 Lu Lutetium 174.97 72 Hf Hafnium 178.49 73 Ta Tantalum 180.95 74 W Tungsten 183.84 75 Re Rhenium 186.21 76 Os Osmium 190.23 77 Ir Iridium 192.22 78 Pt Platinum 195.08 79 Au Gold 196.97 80 Hg Mercury 200.59 81 Tl Thallium 204.38 82 Pb Lead 207.20 83 Bi Bismuth 208.98 84 Po Polonium (208.98) 85 At Astatine (209.99) 86 Rn Radon (222.02) 87 Fr Francium (223.02) 88 Ra Radium (226.03) 89-102 ** 103 Lr Lawrencium (262.11) 104 Rf Rutherfordium (265.12) 105 Db Dubnium (268.13) 106 Sg Seaborgium (271.13) 107 Bh Bohrium (270) 108 Hs Hassium (277.15) 109 Mt Meitnerium (276.15) 110 Ds Darmstadtium (281.16) 111 Rg Roentgenium (280.16) 112 Cn Copernicium (285.17) 113 Nh Nihomium (284.18) 114 Fl Flerovium (289.19) 115 Mc Moscovium (288.19) 116 Lv Livermorium (293) 117 Ts Tennessine
( 294 )
118 Og
Oganesson
GRADE 12 DEPARTMENTAL EXAMINATION
PHYSICS 30, PROTOTYPE EXAM
VALUE 100 (50 2)
Answer the following 50 questions on the computer sheet entitled “Student Examination Form.”
1. Which of the following objects can have its interactions explained using quantum mechanics?
A. electrons B. airplanes C. automobiles D. grains of sand
2. What would happen if you were to accelerate yourself to 90% of the speed of light?
A. your mass decreases, your length expands, and time speeds up B. your mass increases, your length contracts, and time speeds up C. your mass increases, your length contracts, and time slows down D. your mass decreases, your length contracts, and time slows down
4. A student collects data from an unknown light source that travels through a double slit. The following pattern is observed:
Based on this pattern, what is the correct conclusion? A. The source emits waves.
B. The source emits particles.
C. The source emits waves that behave as particles. D. The source emits particles that behave as waves.
5. Alpha radiation is composed of the nuclei of helium atoms. What is the minimum thickness of material needed to stop alpha particles?
A. 2.0 m of air B. a piece of paper
C. 0.5 m thick concrete wall D. 2.0 cm of aluminum metal
6. What particles are necessary for the process of nuclear fusion? A. an atom and a neutron
B. an atom and an electron
C. many atoms that are low energy
7. Which of the following shows the proper alpha decay of thorium?
A. 230 226 4
90Th 88Ra2He
B. 230 228 2
90Th 86Ra4He
C. 230 230 0 0
90Th 91Pa1e0
D. 230 231 1 0
90Th 90Th0e0
NR1. Carbon-11 has a half-life of 20.3 minutes. If a sample contains 35.0 g of the isotope, how much is left after 81.2 minutes? (Round your answer to the nearest g.)
Record your answer in the numeric response section on the answer sheet.
8. Consider the following information.
Nuclide Mass (x 10-27) kg
1
0n 1.675
1
1p 1.673
4
2He 6.647
How much energy is released by the mass defect of helium? A. 1.201 10 J 9
B. 5.982 10 10 J
C. 4.410 10 12 J
9. Which of the following choices shows both a short and a long term effect of radiation?
A. nausea and cancer B. hair loss and vomiting C. birth defects and cancer D. blood changes and nausea
10. The initial velocity of a particle is 2.0 m/s [W]. The final velocity of the particle is 3.0 m/s [E]. Which vector addition diagram below represents the change in velocity, ?
A.
B.
C.
11. Which of the following is a property that all satellites in geosynchronous orbits around the Earth have in common?
A. mass B. altitude C. momentum D. launch time
12. If an object experiences universal circular motion, which characteristic is not constant?
A. speed B. period C. velocity D. acceleration
13. A car moving at a constant speed (v) along a circular road has an
acceleration of 4 m/s . What would be the car’s acceleration if its speed 2
is reduced to 1
2 v?
A. 1 m/s 2
B. 2 m/s 2
C. 8 m/s 2
14. A 1473 kg car is travelling at a constant speed of 100 km/h (27.8 m/s) around a curve on a level roadway. Which of the following statements is true?
A. The acceleration of the car is zero. B. The velocity of the car is constant.
C. The car is travelling with uniform motion.
D. The car is accelerating towards the center of the curve.
15. A toy car is attached to a string and travels in a circular path with a constant speed. The following diagram shows four paths the toy car may follow if the string breaks.
Which path best represents the car’s motion when the string breaks? A. path “A”
16. A wagon moving at 2.0 m/s [E], relative to the ground, has a ball inside that rolls at 1.0 m/s [W], relative to the wagon. What is the velocity of the ball relative to the ground?
A. 1.0 m/s [E] B. 1.0 m/s [W] C. 3.0 m/s [E] D. 3.0 m/s [W]
NR2. An arrow is fired from a bow with a speed of 63.0 m/s at an angle of 34.0°. The arrow hits a target that is the same height as the arrow is shot.
What is the horizontal distance the arrow flies? (Round your answer to the nearest m.)
17. Displacement data is collected in an experiment tracking the motion of a cart as it moves across a frictionless table.
Which set of data represents a cart moving at a constant, non-zero velocity?
A.
B.
C.
D.
t (s) d (m)
0 +3
2 0
4 +3
6 0
t (s) d (m)
0 +3
2 +3
4 +3
6 +3
t (s) d (m)
0 +3
2 0
4 -6
6 -18
t (s) d (m)
0 +3
2 -1
4 -5
18. Data is collected in an experiment tracking the motion of a merry-go-round which has a radius of 7.0 m.
Which set of data represents the displacement of a person travelling with circular motion on the edge of the merry-go-round?
A.
B.
C.
D.
t d
0 s 0
8 s 9.9 m [N45°E]
16 s 14 m [N]
24 s 9.9 m [N45°W]
32 s 0
t (s) d
0 s 0
8 s 9.9 m [N45°E] 16 s 20m [N45°E] 24 s 30m [N45°E] 32 s 40m [N45°E]
t (s) d
0 s 0
8 s 9.9 m [N45°E]
16 s 9.9 m [N]
24 s 9.9 m [N45°W]
32 s 0
t (s) d
0 s 0
8 s 14 m [N]
16 s 0
24 s 14 m [S]
19. Which of the following best illustrates Newton’s first law of motion? A. a car uniformly accelerating
B. a child jumping up to grab a ball C. a cart pulled with a constant velocity D. a baseball player sliding into home plate
20. The London Eye, located on the south bank of the River Thames in London, is a giant Ferris wheel with a radius of 110 m. What is the magnitude and direction of the centripetal force acting on a 65 kg man riding in one of the passenger capsules travelling at a speed of 0.25 m/s? A. 0.037 N [towards centre of wheel]
B. 0.037 N [away from centre of wheel] C. 0.15 N [towards centre of wheel] D. 0.15 N [away from centre of wheel]
21. A helium balloon of negligible mass exerts a force of 256 N [upward] on a 15.0 kg crate. What is the acceleration of the crate?
A. 7.27 m/s2 [upward]
B. 9.81 m/s2 [downward]
C. 17.1 m/s2 [upward]
D. 26.9 m/s2 [downward]
22. An 82.0 kg skydiver is falling at a constant velocity of 57.0 m/s. What is the drag force that air resistance is exerting on the sky diver?
23. A 30 kg object is accelerated by an unbalanced force. How will the acceleration change if the same unbalanced force acts on a 10 kg object? A. 1/3 as large
B. 1/9 as large C. 3 times larger D. 9 times larger
24. A 10 kg mass is pulling down on a 20 kg cart as shown in the diagram.
What is the magnitude of the acceleration of the cart? (Assume no friction.)
A. 0 m/s 2
B. 3.3 m/s 2
C. 4.9 m/s 2
NR3. A 10 kg stone accelerates uniformly at 6.0 m/s2 as it descends to the
ocean floor. What is the magnitude of the force of friction of the water? (Round your answer to the nearest newton.)
Record your answer in the numeric response section on the answer sheet.
25. Consider the following diagram of three forces acting on an object. (Ignore the effects of friction.)
In which direction will the object move? A. southeast
B. northeast C. southwest D. northwest
26. Which of the following would NOT lower the efficiency of a motor? A. friction of the parts
27. A cyclist outputs energy during a 1 hour ride along a flat road. The cyclist’s computer displays measurements of 28 km/h, 2400 J and 200 watts. What can be interpreted from the measurements? A. The cyclist gained 28 m of elevation.
B. The cyclist gained 2400 J of chemical energy.
C. The cyclist is capable of delivering 2400 J of power. D. The cyclist is capable of delivering 200 watts of power.
28. How much work is done when a force of 4.0 N moves a book 0.82 m at 1.2 m/s?
A. 3.3 J B. 3.9 J C. 3.3 10 J 2
D. 3.9 10 J 2
29. A small engine uses 5.2 x 106 J of energy to create an output of 6
1.5 10 J of useful energy. What is the efficiency of the engine? A. 3.5%
NR4. A filing cabinet is pulled a horizontal distance of 4.0 m along a level floor by a 200 N force, as shown in the diagram.
F = 200 N
4.0 m
What is the work done by the force? (Round your answer to the nearest joule.)
Record your answer in the numeric response section on the answer sheet.
30. A 0.48 kg ball is travelling through the air at 15 m/s with a total mechanical energy of 120 J at a given point in time. What is the height (h) of the ball at this moment?
31. A 65 kg person starts from rest on the top of a waterslide 8.0 m above the ground, drops to a height of 4.0 m and then glides back up to a crest 5.0 m high. Ignoring friction and the force exerted by the water, what is the person’s speed at the top of the 5.0 m crest?
A. 5.4 m/s B. 7.7 m/s C. 13 m/s D. 59 m/s
32. A 1.0 g insect flying at 2.0 km/h collides head-on with an 800 kg compact car travelling at 90 km/h. Which object experiences the greater change in momentum during the collision?
A. Neither object experiences a change in momentum. B. The insect experiences the greater change in momentum. C. The compact car experiences the greater change in momentum. D. Both objects experience the same, non-zero change in momentum.
33. Why are hockey and football helmets well padded?
34. A 68.5 kg man and a 41.0 kg woman are standing at rest before
performing a figure skating routine. At the start of the routine, the two skaters push off against each other, giving the woman a velocity of 3.25 m/s [N]. Assuming there is no friction between the skate blades and the ice, what is the man’s velocity due to their push?
A. 1.67 m/s [S] B. 1.95 m/s [N] C. 1.95 m/s [S] D. 3.25 m/s [S]
35. A 15.4 N s impulse is applied to a 5.9 kg medicine ball that is at rest. How fast will the ball roll?
A. 0.38 m/s B. 2.6 m/s C. 5.9 m/s D. 9.6 m/s
36. A 2100 kg truck is travelling at 31 m/s [E] and collides with a 1500 kg car travelling 24 m/s[E]. The two vehicles lock bumpers and continue on as one object.
What is the decrease in kinetic energy during the inelastic collision? A. 3.0 × 104 J
B. 5.8 10 J 5
C. 2.9 10 J 6
37. Two identical satellites are placed into a stable orbit around the Earth. Satellite A is in an orbit that is twice the distance from the Earth than Satellite B. How does the gravitational field strength experienced by Satellite A compare to the gravitational field strength experienced by Satellite B?
A. Satellite A experiences a strength twice that of Satellite B. B. Satellite B experiences a strength twice that of Satellite A. C. Satellite A experiences a strength four times that of Satellite B. D. Satellite B experiences a strength four times that of Satellite A.
38. Some characteristics of the Earth and moon are presented in the table below.
Body Mass Radius
Earth 5.97 10 kg 24 6380 km
Moon 7.34 10 kg 22 1740 km
A student’s mass on Earth is 60.0 kg. What is the student’s mass while standing on the surface of the moon?
39. Albert Einstein proposed a theory of time dilation in his theory of relativity. How will the time shown on an atomic clock located at the base of a mountain relate to the time shown on an identical clock located on the summit of the same mountain?
A. Time will appear to pass more slowly on the clock located at the base of the mountain.
B. Time will appear to pass more quickly on the clock located at the base of the mountain.
C. Time will appear to pass at the same rate on both clocks, as they are identical.
D. Time will appear to pass at the same rate on both clocks, as they are experiencing the same gravitational force.
NR5. A 70 kg person is standing on Jupiter, the largest planet in our solar system, which has a mass of 1.90 x10 kg and a radius of 27 6.99 x10 m. 7
What is the gravitational field strength on Jupiter? (Round your answer to the nearest N/kg.)
Record your answer in the numeric response section on the answer sheet.
40. Two 0.0450 kg golf balls are positioned with their centers of mass 0.0500 m apart. What is the gravitational force of attraction between the two golf balls?
A. 1.20 10 9 N
B. 2.40 10 9 N
C. 5.40 × 10-11 N
41. Consider the following electromagnet set up.
The north pole of the electromagnet is at which letter location? A. A
B. B C. C D. D
42. As the distance between a test charge and a charged particle is varied, the electric field strength changes. If the electric field changes from 50 N/C to 2 N/C, how has the distance to the charged particle changed? A. 5 times greater
43. Consider the following data table.
Electric Field Distance from point charge
Trial #1 3 N/C 1 m
Trial #2 0.7 N/C 2 m
Trial #3 0.3 N/C 3 m
What law does this data prove? A. law of gravity
B. law of magnetism C. inverse square law
D. cannot be determined because the value of q is not given
44. A 2.00 10 C 6 test charge has an electric field strength of 3
1.99 10 N/C acting on it. What is the distance between the test charge and the
electric field source? A. 3.01 m
B. 9.04 m
C. 2.99 10 m 9
45. A coil of wire is wrapped around a hollow, insulated cylinder, as illustrated below.
If the north pole of the bar magnet is moved into the right side of the hollow cylinder, which statement below regarding an electron in the wire at point P is true?
A. The electron will not move.
B. The electron will move to the left. C. The electron will move to the right.
GRADE 12 DEPARTMENTAL EXAMINATION CHEMISTRY 30
PROTOTYPE EXAM — Answer Key
1. A.
Quantum mechanics explains the universe on a sub-atomic particle scale. Newtonian mechanics explains the universe on a macroscopic
(everyday object) scale.
General relativity explains the universe on a cosmological (space-time) scale.
2. C.
Due to time dilation and relativity, time would slow, your length would contract and your mass would increase.
3. B.
The Compton effect is a process where a high energy photon collides with a target and releases loosely bound electrons from the outer shell of the atom.
4. D.
The particles behave as a wave.
5. B.
Alpha particles are large and collide with molecules in the air, slowing down quickly. They are stopped easily by a piece of paper.
6. D.
7. A.
230 226 4
90Th 88Ra 2He
NR1 2 - 3
20.3 minutes 17.5 g 40.6 minutes 8.75 g 60.9 minutes 4.38 g 81.2 minutes 2.19 g (2 g)
8. C.
4 1 1
2 0 1
27 27
27
27 27
29
2
29 8 2
12
He 2 n 2 p
2(1.675 10 ) 2(1.673 10 )
6.696 10 kg
mass defect 6.696 10 6.647 10 4.9 10 kg
E mc
4.9 10 (3 10 ) 4.410 10 J
9. A.
cancer (long term) and nausea (short term)
10. D. v
is defined as vf vi and can be written as vf ( v )i . Students should
11. B.
All geosynchronous satellites orbit at a common altitude of 35800 m above the equator.
The mass of the satellite does not matter, so momentum is not in common even though speed is.
The time of the launch does not matter.
12. C.
If an object is experiencing uniform circular motion, its rate of motion is constant. This means its speed, period (time for a rotation), and acceleration are all constant. The direction the object is travelling is changing as the object goes around the circle, which means the object’s velocity (speed with direction) is not constant.
13. A.
In a v2 R
, if v is divided by 2 and R is not changed, the acceleration is divided by 4.
2 2
4 m/s 4 1m/s
14. D.
For circular motion, the car is accelerating towards the centre of the curve.
15. B.
16. A.
Vector addition:
2.0 m/s R
1.0 m/s
R 1.0 m/s [E]
2.0 m/s [E] 1.0m/s [W] 2.0m/s [E] ( 1.0m/s [E])
1.0 m/s [E]
NR2. 396
x x
y
y
2
2 2
2
2
v 63.0 m/s cos 34.0 v 52.2 m/s [right]
v 63.0 m/s sin 34.0 v 35.2 m/s [up]
1 d vt 2at
1
0 35.2 m/s t 2( 9.81 m/s ) t
t 0 (ignore)
OR
Divide both sides by t to get
1
0 35.2 m/s 2 (9.81 m/s )t
2 * 35.2m/s t
9.81m/s t 7.18 s
d vt
17. D.
Constant velocity will have displacement changing at a constant rate. The data in choice D shows a cart moving forward with a constant velocity of
2 m/s.
18. A.
19. C.
Newton’s 1st Law states that an object will not change its speed or direction unless an unbalanced force affects it. A cart pulled with a constant velocity does not have an unbalanced force acting on it.
20. A.
2
2
mv F
r
(65 kg)(0.25 m/s) F
(110 m)
F 0.037 N [towards centre of wheel]
21. A.
g
2
NET a g
NET
NET
2
F mg
(15.0 kg)(9.81 m/s )
147 N
F F F
F 256 N [upward] 147 N [downward] 109 N [upward]
F ma
109 N [upward] (15 kg) a a 7.27 m/s [upward]
22. B.
Terminal velocity has been reached so Fd = -Fg
23. C.
NET
1 1 2 2
1 2
2
1
F ma m a m a (30 kg) a (10 kg)a
a 30 kg a 10 kg
g
2
F mg
(82 kg)(9.81m/s ) 804 N
24. B. g 2 NET g net g 1 2 2 F mg
(10 kg)(9.81 m/s ) 98.1 N
F F
ma F
(m m )(a) 98.1 N (10 kg 20 kg)(a) 98.1 N 98.1 N a 30 kg 3.3 m/s
NR3. 38
1 2 1
2
2 2
where: Weight( ) Force of friction
(10 kg)(6.0 m/s )[Down] (10 kg)(9.8 m/s )[Down] 60 N [Down] 98 N [Down]
60 N [Down] 98 N [Down] 38 N [Down]
38 N [Up] The m net f f f f f f f
F F F F W mg
F F
ma mg F
F F
F F
F
25. D.
The net force in the x-direction is directed to the west. This works in conjunction with the y-direction force to move the object northwest. Horizontal resultant = 60 N[W] + 30 N [E] = 30 N [W]
Vertical resultant = 30 N [N]
The resultant force will cause the object to move northwest.
26. C.
The more useful the work performed, the higher the efficiency.
27. D.
200 watts is the power generated
2400 J is the amount of energy the cyclist exerted
28 km/h is the speed. It is unknown if this is a maximum, average or minimum.
Height of elevation is not possible to determine.
28. A. W Fd
(4.0 N)(0.82 m) 3.3 J
29. C.
6
1.5 10 J
100 % 29 %
NR4. 725
W Fd cos
(200 N)(4.0 m) cos 25 725 J
30. B.
31. B.
2 2 1 1 2 2 2 2 1 1 2 2 2 1 2 2 1 2 2
mv mgh mv mgh
65(0) 65(9.81)(8) 65(v) 65(9.81)(5) 0 5101.2 65v 3188.25
29.4 v
58.8 v 7.7 m/s v
32. D.
Momentum is conserved, so both the insect and the car will experience the same change in momentum.
T K P
2 T
2 2
E E E
1
E mv mgh
2 1
33. C.
The padding will slow down the collision, so it will take longer to occur, which decreases the force being felt by the player’s head.
34. C.
Momentum is conserved.
m w
m w
m m w w
m
m
0
m v m v
(68.5 kg)v (41.0 kg)(3.25 m/s [N] ) v 1.95 m/s [S]
35. B.
2
Ft m v
15.4 N s 5.8 kg(v 0) 15.4 5.8 v
v 2.6 m/s
36. A.
i
f
f
f
2 2
K 1 1 2 2
2 2
2
K f
2
2100(31) 1500(24) (2100 1500)V 65100 36000 V
3600 28.1 m/s 28 m/s
1 1
E m v m v
2 2
1(2100 kg)(31 m/s) 1(1500 kg)(24 m/s)
2 2
1 009 050 432 000 1 441 050 J
1
E mv
2
1(3600 kg)(28 m/s ) 2
1411 200 J
1 441 050 J 1411 2
4
00 J 29 850 J
3.0 10 J
37. D.
Satellite A experiences a strength one-quarter of that of Satellite B – inverse square rule.
38. B.
39. A.
Time moves more slowly deeper into a gravitational field.
A weaker gravitational field at the top of the mountain will cause time to speed up. Time at the base of the mountain will appear to pass more slowly.
NR5. 25 – 26
2
11 2 2 27
7 2
Gm g
r
(6.67 10 N m /kg )(1.90 10 kg) (6.99 10 m)
25.9 N/kg 25 26 N/kg
40. C.
1 2 2
11 2 2
2
11
Gm m F
r
(6.67 10 N m /kg )(0.0450 kg)(0.0450 kg) (0.0500 m)
5.40 10 N
41. C.
According to the right hand rule, fingers wrap around the bar in the same direction as the coils, following conventional current flow, palm facing away from the page. This places the thumb in the direction of the field – towards position C, the north pole.
42. A.
2
2
50 25 times smaller 2 q r 1 constant r 1 r constant 1 constant 25 1 constant 5
five times larger distance
k
E changed to epsilon in 42, 43 and 44.
43. C.
(1 m) (2 m) (3 m)
- inverse square law
9 10
2
(8.99 10 )(3.337 10 ) 3 0.3 N/C 9 10 2
(8.99 10 )(3.337 10 ) 2 m 0.749 N/C 0.7 N/C 2 2 9 10 q r q 1 m
(8.99 10 )(q) 3
1 3.337 10 q
44. B.
2
9 6
3
(8.99 10 )(2.00 10 ) 1.99 10
q r
q r
r
r 3.006 m
r 3.01 m
k
k
45. B.
Left hand rule is used and “e” current flow moves left.
