PHY2053, Review
Dec 1st, 2013
Final Exam:
Sat, December 7, 12:30-2:30pm Last Name
A-E
F-K
L-O
Room
CLB C130
MCCC 100
FLI 50
Last Name
P-R
S-T
U-Z
Room
WEIL 270
LIT 101
LIT 109
●  Crib sheet: You may bring two hand written formula
sheet on 8½ x 11 inch paper (both sides).
●  Calculator: You should bring a calculator (any type).
●  Scratch Paper: We will provide scratch paper.
PHY2053, Fall 2013, Review, Dec 1, 2013
Distribution of Material
Material
# Problems
Your Exam 1
4
Your Exam 2
4
Chapter 10.5 – 12.8
6
Chapter 1.1 – 10.4
6
PHY2053, Fall 2013, Review, Dec 1, 2013
Make-Up Exam:
Wed, December 4, 5:10–7:00 pm
For anyone who had to miss an exam during the
semester.
●  E-mail to phy2053@phys.ufl.edu, state which exam
you are making up
●  Distribution of material: similar to that of final exam
●  Crib sheet: You may bring two hand written formula
sheet on 8½ x 11 inch paper (both sides).
●  Calculator: You should bring a calculator (any type).
●  Scratch Paper: We will provide scratch paper.
PHY2053, Fall 2013, Review, Dec 1, 2013
H-ITT Questions
Question 1
Online Graded Homework: Which of the following best
expresses your opinion on the WebAssign online homework?
A.  Very important part of the course. I learned a lot by doing
the homework and I think it should be graded.
B.  I learned a lot from the homework, but I would have
preferred that it not be graded.
C.  I learned a little bit by doing the homework and I think it
should be graded.
D.  I learned a little bit by doing the homework, but I would
have preferred that it not be graded.
E.  Complete waste of time. I learned nothing by doing the
homework.
PHY2053, Fall 2013, Review, Dec 1, 2013
Question 2
Quizzes: Which of the following best expresses your opinion
on quizzes in the discussion sections?
A.  Very important part of the course. I learned a lot by doing
the quizzes and I think the grading system was fair.
B.  I learned a lot from the quizzes, but I would have preferred a
different grading system. C.  I learned a little bit by doing the quizzes and I think the
grading system was fair.
D.  I learned a little bit by doing the quizzes, but I would have
preferred a different grading system.
E.  Complete waste of time. I learned nothing by doing the
quizzes.
PHY2053, Fall 2013, Review, Dec 1, 2013
Question 3
The Lectures: Which of the following best expresses your
opinion on the lectures (i.e.coming to class)?
A.  Very important part of the course. I learned a lot from the
lectures and I enjoyed the HITT questions.
B.  I learned a lot from the lectures, but I did not like the HITT
questions.
C.  I learned a little from the lectures and the HITT questions.
D.  I learned a little from the lectures, but I did not like the HITT
questions.
E.  Complete waste of time. I learned nothing by coming to
class.
PHY2053, Fall 2013, Review, Dec 1, 2013
Question 4
Overall Course: Which of the following best expresses your
opinion on what you learned from the course?
A.  I enjoyed the course, and I learned a lot by taking this
course.
B.  I did not enjoy the course, but I learned a lot by taking this
course.
C.  I enjoyed the course, and I learned a little bit by taking this
course.
D.  I did not enjoy the course, but I learned a little bit by taking
this course.
E.  Complete waste of time. I learned nothing from this course.
PHY2053, Fall 2013, Review, Dec 1, 2013
Review: Problems
Problem 1
The keys A4 and B4 on a piano correspond to
frequencies of 440 Hz and 493 Hz, respectively. If these
two keys are played together, what is the beat frequency
of the resulting wave (in Hz)? Answer: 53 Hz
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PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 2
At what height above the Earth’s surface would your
weight be 1/4 of what it is at the surface of the Earth?
(Note: RE is the radius of the Earth.) Answer: RE
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 3
Near the surface of the Earth, a cloth tape is
wound around the outside of the two uniform
solid cylinders shown in the figure. Solid cylinder
1 has mass M1, radius R1, and moment of inertia I1 =½M1R12. Solid cylinder 2 has mass
M2, radius R2, and moment of inertia I2 =½M2R22. Cylinder 2 is attached to the ceiling
and rotates without friction, and cylinder 1 hangs
vertically. If M1 = fM2, when the cylinders are
released from rest and the tape unwinds off both
cylinders, what is the acceleration of the centerof-mass of cylinder 1 (in m/s2)?
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 4
The escape speed from the surface of a planet is the
minimal initial speed a projectile must have to escape
the gravitational pull of the planet. For Earth, the escape
speed is about 11.2 km/s. What is the escape speed (in
km/s) from a planet that has twice the mass of the Earth
and one-half the radius of the Earth? Answer: 22.4 km/s
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 5
The coefficient of static friction between a certain
cylinder with radius R and a horizontal floor is μs. If the
rotational inertia of the cylinder about its symmetry axis
is given by I = MR2/2 and the magnitude of the
maximum translational acceleration the cylinder can
have without sliding is 7.84 m/s2, what is μs? Answer: μs = 0.4
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 6
Two small balls are simultaneously released from rest in
a deep pool of water (with density ρwater). The first ball
is released from rest at the surface of the pool and has a
density 1.5 times the density of water (i.e. ρ1 = 1.5ρwater). A second ball of unknown density is
released from rest at the bottom of the pool. If it takes
the second ball the same amount of time to reach the
surface of the pool as it takes for the first ball to reach
the bottom of the pool, what is the density of the second
ball? Neglect hydrodynamic drag forces. PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 7
Use Bernoulli’s equation to estimate the upward force
(in kN) on an airplane’s wing if the average flow speed
of the air is 200 m/s above the wing and 175 m/s below
the wing. The density of air is 1.3 kg/m3 and the area of
each wing surface is 30 m2. Answer: 183 kN
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 8 A simple harmonic oscillator consists of a block of
mass 2 kg attached to an ideal spring with spring
constant k. If the speed of the block is 20 m/s when the
displacement from equilibrium is 3 m and the amplitude
of the oscillations is 5 m, what is the spring constant k
(in N/m)? Answer: 50 N/m
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 9
A 2,000 kg wrecking ball is to be lifted by a crane with
a steel cable that has a diameter of 2.0 cm and an
unstretched length of 31.4 m. The Young’s modulus of
steel is 2.0 × 1011Pa. Ignoring the weight of the cable
itself, when the ball is lifted and held at rest how much
does the cable stretch (in cm)? Answer: 0.98 cm
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 10
A dangerous highway curve has a radius R = 200 m is
banked in the wrong direction θ = 10º as shown in the
figure. If the static coefficient of friction between the car
and the highway is 0.4, what is the maximum speed the
car can travel around the curve without slipping (in m/
s)? Answer: 20.2 m/s
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 11
A stationary motion detector sends sound waves of
frequency of 500 Hz toward an approaching truck. The
waves sent out by the detector are reflected off the truck
and then are received back at the detector. If the
frequency of the waves received back at the detector is
700 Hz, what is the speed of the approaching truck (in
m/s)? (Take the speed of sound to be 343 m/s.) Answer: 57.2 m/s
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 12
Two traveling pressure waves (wave A and wave B)
have the same frequency and wavelength. The waves
are superimposed upon each other. The amplitude of the
resulting wave (wave C) is 17 kPa. If the amplitude of
wave A is 15 kPa and the phase difference between
wave B and wave A is φB − φA = 90º, what is the
amplitude of wave B and the magnitude of the phase
difference between wave A and wave C, respectively? Answer: 8 kPa, 28.07º PHY2053,
Fall 2013, Review, Dec 1, 2013
Problem 13
Two point masses are located on the x-axis. Mass m1 is
at the origin (i.e., x = 0) and mass m2 is at x = d. If m2 =
2m1, at what point on the x-axis is the net gravitational
force on a test mass m from the two masses equal to
zero? Answer: x = 0.41 d
PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 14
Near the surface of the earth, a conical
pendulum is constructed from a stone of
mass M connected to a cord with length L
and negligible mass. The stone is
undergoing uniform circular motion in the
horizontal plane as shown in the figure. If
the cord makes an angle φ = 40◦ with the
vertical direction and the period of the
circular motion is 3 s, what is the length L
of the cord (in meters)? Answer: 2.92 m
PHY2053,
Fall 2013, Review, Dec 1, 2013
Problem 15
A beanbag is thrown horizontally from a dorm room
window a height h above the ground. It hits the ground
a horizontal distance d = 3h from the dorm directly
below the window from which it was thrown. Ignoring
air resistance, find the direction of the beanbag’s
velocity just before impact. Answer: 33.7º below the horizontal PHY2053, Fall 2013, Review, Dec 1, 2013
Problem 16
A person with a mass of 100 kg stands on one end of a 20-m
long raft. The mass of the raft is 300 kg, and the other end
of the raft is 1 m away from the shore. The person runs as
fast as they can, 10 m/s with respect to the raft. At the end
of the raft, the person jumps upward. In the jump, the
magnitude of the person’s velocity with respect to ground
will stay the same, only its direction will change. Where
will the person land – on ground or in the water?
PHY2053, Fall 2013, Review, Dec 1, 2013