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SAINT PATRICK’S HIGH SCHOOL
PHYSICS 12 ADVANCED
JANUARY 2002 EXAM
Mrs. L. Clarke
Instructions:
1. READ each question very carefully. There are no marks for answering a question
not asked or for neglecting to answer a question.
2. Mark all answers directly on this paper. Use scrap paper if necessary, but it will
not be marked.
3. Scientific calculators and rulers are allowed.
4. Write down as much as you can for each question, but be concise. There are
partial marks for sections B and C.
5. In section B and C where there is choice, only complete the number of questions
indicated (1 / 2 for Section B and 4/5 for Section C). If you do more than the
required number of questions, your answers will be marked in the order that they
appear, and the leftover questions will not be marked.
GOOD LUCK!
Name: ________________________________
Mark:
SECTION A: MULTIPLE CHOICE
Circle the correct answer. There is only one correct answer per question. If more than one answer
is circled or the response is illegible, it will be marked wrong. (1 mark each, 40 marks total)
1. From the top of a cliff 50 m high, an
object is thrown horizontally at a velocity
of 20 m/s. What time does it take for the
object to hit the ground below?
a. 2.3 s
b. 3.2 s
c. 5.1 s
d. 10 s
2. See the diagram below. The total energy
of the projectile at point 3 is
a. mgh
b. ½ mv12
c. ½ mv12 + mgh
d. ½ mv12 – mgh
3. See the diagram for #2. The kinetic
energy of the projectile at point 3 is
a. mgh
b. ½ mv12
c. ½ mv12 + mgh
d. ½ mv12 – mgh
4. See the diagram for #2. The total energy
of the projectile at point 2 is
a. mgh
b. ½ mv12
c. ½ mv12 + mgh
d. ½ mv12 – ½ mgh
5. A car is rounding a flat curve of radius 50
m with a speed of 20 m/s. The centripetal
force provided by friction is 1.2 104 N.
What is the mass of the car?
a. 500 kg
b. 1000 kg
c. 1500 kg
d. 2000 kg
6. A 0.50 kg mass is attached to the end of a
1.0 m string. The system is whirled in a
horizontal circular path. If the maximum
tension that the string can withstand is 350
N, what is the maximum speed that the
mass can have if the string is not to break?
a. 700 m/s
b. 26 m/s
c. 19 m/s
d. 13 m/s
7. Let the average orbital radius of a planet
be R. Let the orbital period of the planet
be T. Which of the following is constant
for all planets orbiting the same sun?
a. T/R
c. T2/R3
2
b. T/R
d. T3/R2
8. A car goes around a curve of radius r at a
constant speed of v. Then it goes around
another curve, of radius 2r and at a
constant speed of 2v. What is the
centripetal acceleration of the car as it
goes around the second curve, as
compared to on the first curve?
a. ½ as large
b. the same
c. twice as large
d. four times as large
9. The speed of Halley’s comet, while
traveling in its elliptical orbit around the
sun,
a. Is constant
b. increases as it nears the sun
c. decreases as it nears the sun
d. is zero at two points in its orbit
10. Europa is one of the moons of Jupiter. It
has an orbital radius 9.40 times the radius
of Jupiter. Its period is 85.2 hours.
Callisto, another of Jupiter’s moons, has
an orbital radius 26.4 times the radius of
Jupiter. What is Callisto’s period?
a. 1.70  102 hr
b. 2.39  102 hr
c. 4.01  102 hr
d. 1.61  105 hr
11. Which of the following can be used to
calculate the acceleration due to gravity
on any planet?
a. Gmp/rp
c. Grp2/mp
b. Gmp/rp2
d. Grp2/mp2
12. The gravitational attractive force between
two masses is F. If the masses are moved
to half of their original distance, what is
the new gravitational attractive force?
a. F/4
b. F/2
c. 2F
d. 4F
13. Who was the first person to realize that
the planets move in elliptical orbits, and
not circular ones, around the sun?
a. Johannes Kepler
b. Isaac Newton
c. Albert Einstein
d. Mrs. Clarke
14. A 500 kg elevator is pulled upward with a
constant force of 5500 N for a distance of
50.0 m. What is the work done by the
5500 N force?
a. 2.75  105 J
b. – 2.45  105 J
c. 3.00  104 J
d. – 5.20  105 J
15. Does the centripetal force acting on an
object moving in a circle at constant speed
do work on the object?
a. Yes, since a force acts and the object
moves, and work is force times
distance.
b. Yes, since it takes energy to turn an
object.
c. No, because the object has constant
speed.
d. No, because the force and the
displacement of the object are
perpendicular.
16. What is the period of a pendulum with a
length of 0.750 m?
a. 0.481 s
b. 1.74 s
c. 4.71 s
d. 5.44 s
17. A spring-driven dart gun propels a 10 g
dart. Work is done on the dart by
exerting an average force of 20 N over a
distance of 5.0 cm. With what speed
will the dart leave the gun, assuming the
spring has negligible mass?
a. 10 m/s
b. 14 m/s
c. 17 m/s
d. 20 m/s
18. You slam on the brakes of your car in a
panic, and skid a certain distance on a
straight, level road. If you had been
traveling twice as fast, what distance
would the car have skidded, if all other
conditions were the same?
a. 4 times farther
b. Twice as far
c.
2 times farther
d. Not enough information
19. Which of the following statements
correctly expresses the value of Fnet on
the box on the incline shown in the
diagram? ([up the ramp] is positive.)
a. -Fgsin - Ff +Fapp
b. -Fgcos - Ff +Fapp
c. Fapp + Ff – Fgsin
d. Fapp + Ff + Fgcos
Fapp
21. A brick is moving at a speed of 3 m/s
and a pebble is moving at a speed of 5
m/s. If both objects have the same
kinetic energy, what is the ratio of the
brick’s mass to the pebble’s mass?
a. 25 to 9
b. 5 to 3
c. 12.5 to 4.5
d. 3 to 5
22. A lightweight object and a very heavy
object are sliding with equal speeds
along a level frictionless surface. They
both slide up the same frictionless hill.
Which rises to a greater height?
a. The heavy object, because it has
greater kinetic energy.
b. The lighter object, because it weighs
less.
c. They both slide to the same height.
d. Not enough information.
23. A student standing on top of a building
throws a ball with a horizontal velocity
of 12 m/s. If the ball strikes the ground
45 m from the base of the building, how
high is the building?
a. 18 m
b. 37 m
c. 69 m
d. 140 m
24. How many joules of energy are used by
a 1.0 horsepower motor that runs for 1.0
hours? (Note: 1 h.p. = 746 W)
a. 3.6  103 J
b. 2.7  106 J
c. 4.5  104 J
d. 4.8 J
25. A person drops a ball while standing on
a train moving at constant speed along a
horizontal track. What path does a
person at rest, off the train, see the ball
take?
a. A straight path down
b. A parabolic path with motion in the
direction opposite to that of the
train’s motion
c. A parabolic path with motion in the
direction of the train’s motion
d. A straight path angled forward in
the direction of the train’s motion
m
θ
Direction of
motion
20. A skier, with mass 40 kg, pushes off the
top of a hill with an initial speed of 4.0
m/s. Neglecting friction, how fast will
she be moving after dropping 10 m in
elevation?
a. 7.3 m/s
c. 49 m/s
b. 14.5 m/s
d. 196 m/s
26. A 0.060 kg tennis ball, initially moving
at a speed of 12 m/s, is struck by a
racket causing it to rebound in the
opposite direction at a speed of 18 m/s.
What is the ball’s change in
momentum?
a. 0.36 kgm/s
b. 0.72 kgm/s
c. 1.1 kgm/s
d. 1.8 kgm/s
27. A 50 kg pitching machine (this mass is
excluding the baseball) is placed on a
frozen pond. The machine fires a 0.40
kg baseball with a speed of 35 m/s in the
horizontal direction. What is the recoil
speed of the pitching machine? (Assume
friction is negligible.)
a. 0.14 m/s
b. 0.28 m/s
c. 0.70 m/s
d. 4.4  103 m/s
28. A 3.0 kg object moves to the right at 4.0
m/s. It collides head-on with a 6.0 kg
object moving to the left at 2.0 m/s.
Which statement is correct?
a. The total momentum both before
and after the collision is 24 kgm/s.
b. The total momentum before the
collision is 24 kgm/s and after the
collision is 0 kgm/s.
c. The total momentum both before
and after the collision is 0 kgm/s.
d. None of the above is correct.
29. A railroad freight car, mass 15 000 kg,
is allowed to coast along a level track at
a speed of 2.0 m/s. It collides and locks
with a 50 000 kg second car, initially at
rest and with brakes released. What is
the speed of the two cars after they stick
together?
a. 0.46 m/s
c. 1.2 m/s
b. 0.60 m/s
d. 1.8 m/s
30. A 4.0 N force acts for 3.0 s on an object.
The force suddenly increases to 15 N
and acts for one more second. What
total impulse was imparted by these
forces to the object?
a. 12 Ns
b. 15 Ns
c. 16 Ns
d. 27 Ns
31. A ping pong ball moving East at a speed
of 4 m/s collides with a stationary
bowling ball. The ping pong ball
bounces back to the West, and the
bowling ball moves very slowly to the
East. Which object experienced the
greater magnitude of impulse during the
collision?
a. Neither, both experienced the same
magnitude of impulse.
b. The ping pong ball
c. The bowling ball
d. Not enough information
32. In an elastic collision, which of the
following statements is true?
a. Kinetic energy is conserved
b. Kinetic energy is gained
c. Kinetic energy is lost
d. None of the above
33. The distance from the Earth to our Sun
is 8.3 light-minutes, which means
a. 4.15  107 m
b. 1.49  1011 m
c. 1.66  10-6 m
d. 6.02  105 m
34. Cosmology means
a. Using physics to study the heavens
b. The study of planets and stars
c. The study of Kramer on Seinfeld
d. The study of the universe as a whole
35. The term “nebula” currently refers to
a. A glowing cloud of gas or dust
b. A group of galaxies
c. Something outside our galaxy
d. A quasar
36. Einstein’s principle of equivalence says
a. All frames of reference are
equivalent
b. An accelerating reference frame
causes fictional forces
c. Space is non-linear
d. Gravitational mass is the same as
inertial mass
37. A “closed universe” is most like:
a. A sheet that folds back in on itself
b. An infinite, never-ending sheet
c. A rubber sheet with a heavy weight
in the middle
d. A sheet where the angles of a
triangle add up to less than 180
38. The “missing mass” or dark matter
might be found in
a. WIMPS
b. Quasars
c. White dwarfs
d. All of these
39. If the mass density of the universe is
less than  c  10 26 kg/m3, then
a. The universe is contracting
b. The universe is expanding
c. The universe is staying the same
size
d. The universe is dying
40. The idea that life could not exist if any
of the fundamental physical constants
were even slightly different is called
a. The deceleration parameter
b. The radiation-dominated universe
c. The big crunch
d. The Anthropic principle
SECTION B: ESSAY QUESTION
Choose ONLY ONE of the following questions. Answer as completely as possible. If
necessary, use the back of a page for extra space, but please indicate if you do so. (10 marks)
1. A metal ball is dropped at the same instant that a pellet is fired from a launcher as shown
in the diagram. The pellet leaves the muzzle of the launcher at a velocity of 53.0 m/s in
the direction of the metal ball.
In a few sentences, describe the motion
of the pellet, the motion of the ball, and
why the pellet and the ball will collide.
OR
2. Students set up a glider and some springs on an air track as shown.
The glider is pulled in one direction away from the equilibrium position and released. In a
sentence, describe what happens to each of the following in each case:
a) What happens to the period of the glider if the initial displacement of the glider is
increased?
b) What happens to the restoring force of the system as the glider moves farther from
the equilibrium position?
c) What happens to the speed of the glider as it moves farther from the equilibrium
position?
d) What happens to the period of the glider if the mass of the glider is increased?
SECTION C: PROBLEMS: Do ONLY four (4) of the five questions. YOU MUST
ANSWER #1. Answer as fully as possible, using correct units and significant figures. It is helpful if a
sentence is written to summarize the answer(s). (10 marks each, 40 marks total)
YOU MUST ANSWER THIS QUESTION.
1.
The diagram shows two vehicles about to collide. Car A has a mass of 1500 kg and a speed of
50.0 km/hr in the direction indicated. Car B has a mass of 1200 kg and a speed of 40.0 km/hr in
the direction indicated. When they collide, the two cars remain stuck together.
a.
Draw a scale diagram showing the momentum of each vehicle before the impact, the total
momentum before impact, and the total momentum after the impact. (3 pts)
b.
Determine the final velocity of the combined mass after the impact. (4 pts)
c.
How does the total kinetic energy after the impact compare quantitatively to the total kinetic
energy before the impact? (i.e. give a percentage) (3 pts)
NOW CHOOSE 3 OF THE REMAINING 4 QUESTIONS.
2.
Determine the coefficient of friction on the table in the diagram below, if the system moves at
constant, non-zero speed. Start with FBDs and show all necessary steps. (10 pts)
2.5 kg
1.5 kg
3.
A 150 g pendulum bob is drawn aside from its equilibrium position to an angle of 15. The length
of the pendulum string is 58 cm. Determine
4.
a.
The speed of the bob as it passes through its equilibrium position (4 pts)
b.
The period of the SHM of the bob (3 pts)
c.
The tension in the string as the bob passes through the equilibrium position. (4 pts)
A 250 g ball is whirled in a horizontal circle on a 1.2 m long string. The tension in the string is
11.2 N. The string suddenly breaks and the ball becomes a projectile.
a.
Draw a diagram of what would happen to the ball after the string breaks, demonstrating what
you know about circular motion and projectiles. (3 pts)
b.
Determine the horizontal distance the ball would land from the center of the circle, if it was
released at a height of 1.8 m. (7 pts)
5.
In the diagram shown, the mass m is released from the height h and travels around the circular,
frictionless track. Derive a formula for the minimum height h from which the mass must be
released to travel around the circle, in terms of only the radius r of the circle. Show all steps
clearly. (10 marks)
m
h
r
SECTION D: BONUS QUESTION (3 pts possible) Show answer on back of this page.
After a completely inelastic collision between two objects of equal mass, each having initial speed v,
the two objects move off together with speed v/3. What was the angle between their initial velocities?
-----------------------------------------------------------------------------------------------------In this space, you may make any reasonable suggestions or comments on the course, if you like: