1. science
2. physics

PHYS 211 – Final Exam
Fall 2012
Sample 1
1) A pilot drops a package from a plane flying horizontally at a constant speed.
Neglecting air resistance, when the package hits the ground the horizontal location of
the plane will
A. be behind the package.
B. be over the package.
C. be in front of the package.
D. depend of the speed of the plane when the package was released.
2) A squirrel moves along an x axis. In which case below is the sign of the acceleration
positive?
A.
B.
C.
D.
E.
The squirrel moves in the positive direction with decreasing speed
The squirrel moves with decreasing speed in the negative direction.
The squirrel moves in the negative direction with increasing speed
The squirrel comes to rest after moving in the positive direction
None of the above
3) A car travels around a circular track with a constant angular velocity. Which of the
following can be true?
A.
B.
C.
D.
E.
its velocity is constant
its speed is constant
the direction of its velocity is constant
the magnitude and direction of the velocity are constant
all of the above
4) A long uniform board has a mass of 10 kilograms. It rests on a pivoting support at its
midpoint. Two children, with masses of 20 kilograms and 30 kilograms, stand on the
board on opposite sides of the pivot so that the board is balanced. What,
approximately, is the upward force exerted on the board by the support?
A.
B.
C.
D.
E.
100 N
200 N
300 N
500 N
600 N
PHYS 211 – Final Exam
Fall 2012
5) A 500-g particle is located at the point
velocity
= 5 m/s
= 4m + 3m - 2m
Sample 1
and is moving with a
-2 m/s + 4 m/s . What is the angular momentum of this particle
about the origin?
A. (24 - 6 - 8 ) kg∙m2/s
B. (12 - 3 - 4 ) kg∙m2/s
C. (8 + 14 - 13 ) kg∙m2/s
D. (10 - + 2 ) kg∙m2/s
E. (4 - 13 - 11.5 ) kg∙m2/s
6) A solid cylinder and a hollow cylinder, both of the same radius but different masses,
are rolling across the floor (with negligible rolling friction) with the same velocity. They
then roll up identical ramps. What is true of the maximum heights each are able to roll
up the ramp?
A.
B.
C.
D.
They roll to the same height
The solid cylinder rolls higher
The hollow cylinder rolls higher
It is impossible to tell without knowing their relative masses
7) The displacement of an object oscillating on a spring is given by x(t) = xm cos(t +
). If the initial displacement is zero and the initial velocity is in the negative x direction,
then the phase constant  is:
A.
B.
C.
D.
E.
0
/2 rad
 rad
/2 rad
 rad
PHYS 211 – Final Exam
Fall 2012
Sample 1
8) A heavy boy and a lightweight girl are balanced on a massless seesaw. If they both
move forward so that they are one-half their original distance from the pivot point, what
will happen to the seesaw? Assume that both people are small enough compared to the
length of the seesaw to be thought of as point masses.
A.
B.
C.
D.
E.
It is impossible to say without knowing the masses.
It is impossible to say without knowing the distances.
The side the boy is sitting on will tilt downward.
Nothing will happen; the seesaw will still be balanced.
The side the girl is sitting on will tilt downward.
9) Identical guns fire identical bullets horizontally at the same speed from the same
height above level planes, one on the Earth and one on the Moon. Which of the
following three statements is/are true if we ignore air resistance?
I.
II.
III.
A.
B.
C.
D.
E.
The horizontal distance traveled by the bullet is greater for the Moon.
The flight time is less for the bullet on the Earth.
The velocity of the bullets at impact are the same.
III only
I and II only
I and III only
II and III only
I, II, III
PHYS 211 – Final Exam
Fall 2012
Sample 1
10) Two objects are moving in the x, y plane as shown. The magnitude of their total
angular momentum (about the origin O) is:
A.
B.
C.
D.
E.
zero
6 J· s
12 J· s
18 J· s
30 J· s
11) A simple pendulum of length L and mass M has frequency f. To increase its
frequency to 2f:
A.
B.
C.
D.
E.
increase its length to 4L.
increase its length to 2L.
decrease its length to L/2.
decrease its length to L/4.
decrease its mass to <M/4.
PHYS 211 – Final Exam
Fall 2012
Sample 1
12) The acceleration of an object as a function of time is given by a(t) = (3.00 m/s3)t,
where t is in seconds. If the object is at rest at time t = 0.00 s, what is the velocity of the
object at time t = 6.00 s?
A. 18.0 m/s
B. 54.0 m/s
C. 0.00 m/s
D. 15.0 m/s
E. 108 m/s
13) Two friends are standing at rest on opposite ends of a uniform horizontal wooden
board. The board is at rest, and it is balanced in its middle on a triangular post. You
observe that Friend A is three times closer to the center of the board than Friend B.
Which of the following statements is false?
A.
B.
C.
D.
E.
Friend A is three times heavier than Friend B.
The total torque on the board around any point is zero.
The total force on Friend B is zero.
The board must be massless for this situation to be possible.
The total torque on Friend B is zero.
14) A pendulum consists of a 100 g block of wood on a 20 cm long string. The
pendulum is held out horizontally (the string is parallel to the floor) and then released,
allowing the block to swing downward. A pellet gun (muzzle velocity 200 m/s) is fired at
the block just as it reaches the bottom. The pellet embeds in the pendulum block and
immediately brings it to rest at the bottom of the motion. What was the mass of the
pellet used? As always, use g = 10 m/s2.
A.
B.
C.
D.
E.
10 mg
1g
10 g
100 g
None of the above
PHYS 211 – Final Exam
Fall 2012
Sample 1
15) A flying saucer deep in interstellar space, free of external forces and torques,
rotates about its symmetry axis with angular velocity . The aliens inside the saucer
rearrange the furniture to make room for a Christmas tree they have just procured from
Elvis. As a result, the angular velocity of the saucer increases to 2. If originally the
rotational kinetic energy of the saucer was K, after the rearrangement its new rotational
kinetic energy is:
A. K/4
B. K/2
C. K
D. 2K
E. 4K
16) A mass m is thrown downward with an
initial speed vo a height hi above a table top on
which sits a spring with spring constant k.
The mass compresses the spring by a
maximum amount x and stops for an instant at
a height hf. There is no friction in this
problem. Which of the following equations
correctly expresses conservation of energy
and allows one to solve for the compression x
of the spring?
A.
mgh i  12 mvo2  12 kx 2
B.
mghi  12 mvo2  12 kx 2  mgh f
C.
mgh i  12 kx 2  mgh f
D. mg  h f  h i   12 kx  12 mvo
E. None of these equations is correct.
2
2
m
vo
hi
k
x
hf
PHYS 211 – Final Exam
Fall 2012
Sample 1
17) A wheel spinning at 4 revolutions per second is torqued so as to accelerate with
angular acceleration 2 rev/s2. What will its angular velocity be after 5 revolutions?
A.
B.
C.
D.
E.
2 5 rev/s
6 rev/s
14 rev/s
20 rev/s
None of the above
18) Consider a pair of gears, as shown in the figure at right. Gear A has a radius R and
20 teeth while gear B has twice the
radius and twice the teeth. Both gears
are free to rotate on frictionless
bearings about their centers, but they
are locked relative to each other (if one
turns by 5 teeth, so does the other).
Compare the torque that A exerts on B
 τ A B  about B’s center to the torque B
exerts on A  τ B
A
 about A’s center.
A. τ A
B
 τB
B. τ A
B
 τB
A
C. τ A
B
 2τ B
A
D. τ A
B
 2τ B
A
A
E. Not enough information to determine
19) The amplitude of a system moving with simple harmonic motion is doubled. The
maximum velocity of the object will then be:
A.
B.
C.
D.
E.
4 times larger.
3 times larger.
2 times larger.
same as it was.
half as much.
PHYS 211 – Final Exam
Fall 2012
Sample 1
20) Two identical disks, with rotational inertia I (= 1/2MR2), roll without sliding across a
horizontal floor with the same speed and then up inclines. Disk A rolls up its incline
without sliding. On the other hand, disk B rolls up a frictionless incline. Otherwise the
inclines are identical. Disk A reaches a height 12 cm above the floor before rolling down
again. Disk B reaches a height above the floor of:
A. 24 cm
B. 18 cm
C. 12 cm
D. 8 cm
E. 6 cm
21) The figure shows a small block of mass
m that can slide along the frictionless loopthe-loop. The block is released from rest at
point P, at height h = 10R above the bottom
of the loop. What is the normal force on the
block at the top of the loop (point Q)?
A.
B.
C.
D.
E.
20mg
17mg
16mg
15mg
None of the above
PHYS 211 – Final Exam
Fall 2012
Sample 1
22) The velocity v(t) of a particle undergoing Simple Harmonic Motion is graphed in the
figure. If the amplitude of the motion is xm, what is the particle's position when its
velocity is represented by point A? (Hint: what is the phase of the motion here?)
A.
B.
C.
D.
E.
at +xm
between -xm and 0
at 0
between 0 and + xm
at -xm
23) In the following situation, a force F pulls on the lower
block M. A horizontal rope fastens the upper block m to the
wall (the tension in the rope is T). The two blocks and the
floor are made of wood, and the coefficient of kinetic friction
for wood rubbing against wood is K. Which of the following
statements is true?
A.
B.
C.
D.
E.
The vertical force exerted on M by the ground is equal to Mg.
The tension T in the rope is equal to F.
The sum of all frictional forces on M is K(2m+M)g.
If M is moving at constant speed, then F=K(2m+M)g + T
More than one of the above
PHYS 211 – Final Exam
Fall 2012
Sample 1
24) A small plane flies directly between two local airports with a tailwind of 50 mph. On
the return trip it flew with 50% faster airspeed, but as the wind hadn’t changed the return
trip took the same time. What was the original airspeed of the plane?
A. 50 mph
B. 100 mph
C. 150 mph
D. 200 mph
E. 250 mph
25) A child (mass M) gets on a playground swing at pushes herself back to start one m
above her low point of the swing. What will the tension in the 3 m long rope supporting
the swing be at the bottom of her motion?
A.
B.
C.
D.
E.
Mg
5 Mg/3
4 Mg/3
2 Mg/3
Mg/3