Download AP Physics This and Samples

AP Physics
This-and-That Test Samples
Rotational Equilibrium, Gravity, & Oscillations
4) The acceleration due to gravity on the surface
of Earth is g. Calling R the radius of Earth, at
what distance from Earthʹs center would the
acceleration due to gravity drop to g/16?
A) R/16
B) 2 R
C) R/4
D) 16 R
E) 4 R
MULTIPLE CHOICE. Choose the one alternative that
best completes the statement or answers the question.
1) A mass of 0.250 kg is attached to a spring and
undergoes simple harmonic oscillations with a
period of 0.640 s. What is the force constant of
the spring?
A) 0.102 N/m
B) 12.1 N/m
C) 2.45 N/m
D) 24.1 N/m
E) 0.610 N/m
5) A mass on a spring undergoes SHM. When
the mass is at maximum displacement from
equilibrium, its instantaneous acceleration
A) is zero.
B) is a maximum.
C) is less than maximum, but not zero.
D) cannot be determined without mass
information given.
E) cannot be determined without spring
constant information given.
2) For periodic motion, the maximum
displacement from the equilibrium point is
called the
A) energy.
B) amplitude.
C) frequency.
D) period.
E) wavelength.
3) A mass is attached to a vertical spring and
bobs up and down between points A and B.
Where is the mass located when its potential
energy is a minimum?
A) midway between A and B
B) one-fourth of the way between A and B
C) one-third of the way between A and B
D) at either A or B
E) none of the above
1
8) The total mechanical energy of a simple
harmonic oscillator is
A) zero as it passes the equilibrium point.
B) zero when it reaches the maximum
displacement.
C) a maximum when it passes through the
equilibrium point.
D) constant.
E) a minimum when it passes through the
equilibrium point.
FIGURE 11-2
6) A croquet mallet balances when suspended
from its center of mass, as shown in Figure
11-2. If you cut the mallet in two at its center
of mass, as shown, how do the masses of the
two pieces compare?
A) The masses are equal.
B) The piece with the head of the mallet has
the smaller mass.
C) The piece with the head of the mallet has
the greater mass.
D) It is impossible to tell.
9) The gravitational force between two objects is
inversely proportional to
A) the square of the distance between the
two objects.
B) the product of the masses of the two
objects.
C) the square of the product of the masses
of the two objects.
D) the distance between the two objects.
E) none of the above
7) A 15.0-kg child is sitting on a playground
teeter-totter, 1.50 m from the pivot. What is
the minimum distance, on the other side of the
pivot, such that a 220-N force will make the
child lift off the ground?
A) 0.102 m
B) 1.50 m
C) 2.35 m
D) 9.78 m
E) 1.00 m
10) A sewing machine needle moves with a
frequency of 2.5 Hz. Approximately how long
does it take it to move from the highest point
to the lowest point in its travel?
A) 0.20 s
B) 1.25 s
C) 0.40 s
D) 0.10 s
E) 0.80 s
2
14) An astronaut has landed on an asteroid and
conducts an experiment to determine the
acceleration of gravity on that asteroid. She
uses a pendulum that has a period of
oscillation of 2.00 s on Earth and finds that on
the asteroid the period is 11.3 s. What is the
acceleration of gravity on that asteroid?
A) 0.307 m/s2
11) The time for one cycle of a periodic process is
called the
A) frequency.
B) energy.
C) period.
D) wavelength.
E) amplitude.
B) 1.66 m/s2
C) 0.0544 m/s2
D) 1.74 m/s2
E) 5.51 m/s2
12) When the mass of a simple pendulum is
tripled, the time required for one complete
vibration
A) decreases to 1/ 3 of its original value.
B) increases by a factor of 2.
C) increases by a factor of 3.
D) does not change.
E) decreases to one-third of its original
value.
15) A mass m is attached to a vertical spring with
a force constant k, it oscillates with a period T.
If the spring is cut to one third of its original
length and the same mass is attached to it, the
new period of oscillation will be
A) less than T.
B) equal to T.
C) greater than T.
D) It could be greater or less than T,
depending on how you cut the spring.
13) In simple harmonic motion, the acceleration is
proportional to
A) the velocity.
B) the displacement.
C) the frequency.
D) the amplitude.
E) all of the above
16) Two equal forces are applied to a door at the
doorknob. The first force is applied
perpendicular to the door; the second force is
applied at 30° to the plane of the door. Which
force exerts the greater torque?
A) both exert equal non-zero torques
B) the second applied at an angle
C) both exert zero torques
D) the first applied perpendicular to the
door
E) Additional information is needed.
3
TRUE/FALSE. Write ʹTʹ if the statement is true and ʹFʹ if
the statement is false.
FIGURE 11-5
17) The reason that when an object falls towards
Earth, Earth does not move toward the object,
is that the force exerted by Earth on the object
is so much bigger.
19) An 82.0 kg-diver stands at the edge of a light
5.00-m diving board, which is supported by
two pillars 1.60 m apart, as shown in Figure
11-5. Find the force exerted by pillar A.
A) 1.71 kN downwards
B) 2.51 kN downwards
C) 1.71 kN upwards
D) 3.44 kN upwards
E) 2.51 kN upwards
MULTIPLE CHOICE. Choose the one alternative that
best completes the statement or answers the question.
18) A mass on a spring undergoes SHM. When
the mass is at its maximum displacement from
equilibrium, its instantaneous velocity
A) is less than maximum, but not zero.
B) is maximum.
C) is zero.
D) cannot be determined without mass
information given.
E) cannot be determined without spring
constant information given.
20) Because Earthʹs orbit is slightly elliptical, Earth
actually gets closer to the Sun during part of
the year. When Earth is closer to the Sun its
orbital speed is
A) sometimes greater sometimes smaller
than when Earth is farthest away from
the Sun.
B) the same as when Earth is farthest away
from the Sun.
C) less than when Earth is farthest away
from the Sun.
D) greater than when Earth is farthest away
from the Sun.
4
21) A man is holding an 8.00-kg vacuum cleaner
at armʹs length, a distance of 0.550 m from his
shoulder. What is the torque on the shoulder
joint if the arm is horizontal?
A) 43.2 Nm
B) 14.5 Nm
C) 0.242 Nm
D) 4.40 Nm
E) 0 Nm
24) Two objects attract each other gravitationally.
If the distance between their centers
is cut in half, the gravitational force
A) doubles.
B) is cut in half.
C) quadruples
D) is cut to one fourth.
25) A mass is attached to a vertical spring and
bobs up and down between points A and B.
Where is the mass located when its kinetic
energy is a minimum?
A) midway between A and B
B) one-third of the way between A and B
C) one-fourth of the way between A and B
D) at either A or B
E) none of the above
22) A mass is attached to a spring and oscillates
with a period T. If the mass is doubled, what is
the new period?
A) T
B) T/2
C) T/ 2
D) T 2
E) 2T
26) The hydrogen atom consists of a proton of
mass 1.67 × 10-27 kg and an orbiting electron
of mass 9.11 × 10-31 kg. In one of its orbits,
the electron is 5.3 × 10-11 m from the proton.
What is the mutual attractive gravitational
force between the electron and proton?
A) 3.6 × 10-47 N
B) 1.8 × 10-47 N
C) 5.4 × 10-47 N
D) 9.3 × 10-47 N
E) 7.0 × 10-47 N
23) A simple pendulum consists of a mass M
attached to a weightless string of length L. For
this system, when undergoing small
oscillations
A) the frequency is independent of the
length L.
B) the frequency is inversely proportional to
the amplitude.
C) the frequency is proportional to the
amplitude.
D) the period is proportional to the
amplitude.
E) the frequency is independent of the mass
M.
5
27) What would be the weight of a 59.1-kg
astronaut on a planet twice as massive as Earth
and having twice Earthʹs radius?
A) 1160 N
B) 290 N
C) 580 N
D) 1200 N
E) 118 N
30) Two planets have the same surface gravity,
but planet B has twice the radius of planet A.
If planet A has mass m, what is the mass of
planet B?
A) 4m
B) m
C) 1.41m
D) 0.707m
31) When a mass of 0.350 kg is attached to a
vertical spring and lowered slowly, the spring
stretches a distance d. The mass is now
displaced from its equilibrium position and
undergoes 100 oscillations in 48.9 s. What is
the stretch distance d?
A) 2.35 cm
B) 4.71 cm
C) 6.28 cm
D) 5.94 cm
E) 2.97 cm
28) A pendulum that was originally erected by
Foucault at the Pantheon in Paris for the Paris
Exhibition in 1851 was restored in 1995. It has
a 28.0 kg sphere suspended from a 67.0-m
light cable. How long would it take for the bob
in this pendulum to move from the position of
maximum displacement back to the
equilibrium point?
A) 4.11 s
B) 32.2 s
C) 2.58 s
D) 21.5 s
E) 42.9 s
32) Doubling only the amplitude of a vibrating
mass-and-spring system produces what effect
on the systemʹs mechanical energy?
A) increases the energy by a factor of three
B) increases the energy by a factor of two
C) increases the energy by a factor of four
D) increases the energy by a factor of square
root of two
E) produces no change
29) In a supermarket, you place a 5 lb (22.3 N) bag
of oranges on a scale. The scale starts to
oscillate at 2.70 Hz. What is the force constant
of the scale?
A) 327 N/m
B) 602 N/m
C) 409 N/m
D) 654 N/m
E) 819 N/m
6
33) A mass oscillates on the end of a spring, both
on Earth and on the Moon. Where is the
period the greatest?
A) the Moon
B) Earth
C) the same on both Earth and the Moon
D) Cannot be determined from the
information given.
36) If you take a given pendulum to the Moon,
where the acceleration of gravity is less than
on Earth, the resonant frequency of the
pendulum will
A) become zero.
B) increase.
C) decrease.
D) not change.
E) either increase or decrease; it depends on
its length to mass ratio.
34) A pendulum of length L is suspended from the
ceiling of an elevator. When the elevator is at
rest the period of the pendulum is T. How
does the period of the pendulum change when
the elevator moves upward with constant
acceleration?
A) The period decreases.
B) The period does not change.
C) The period increases.
D) The period becomes zero.
E) The period increases if the upward
acceleration is more than g/2 but
decreases if the upward acceleration is
less than g/2.
37) If your heart is beating at 76.0 beats per
minute, what is the frequency of your heartʹs
oscillations?
A) 2.54 Hz
B) 1450 Hz
C) 4560 Hz
D) 1.27 Hz
E) 3.98 Hz
35) The mass of the Moon is 7.4 × 1022 kg and its
mean radius is 1.75 × 103 km. What is the
acceleration due to gravity at the surface of the
Moon?
A) 0.80 m/s2
B) 1.6 m/s2
C) 9.80 m/s2
D) 2.8 × 106 m/s2
7
Answer Key
Testname: AP THIS+THAT TEST SAMPLE
1) D
24) C
Diff: 1
Diff: 1
2) B
25) D
Diff: 1
Diff: 2
3) A
26) A
Diff: 2
Diff: 1
4) E
27) B
Diff: 1
Diff: 1
5) B
28) A
Diff: 1
Diff: 1
6) C
29) D
Diff: 1
Diff: 1
7) E
30) A
Diff: 2
Diff: 2
8) D
31) D
Diff: 1
Diff: 2
9) A
32) C
Diff: 1
Diff: 1
10) A
33) C
Diff: 1
Diff: 2
11) C
34) A
Diff: 1
Diff: 1
12) D
35) B
Diff: 1
Diff: 1
13) B
36) C
Diff: 1
Diff: 1
14) A
37) D
Diff: 1
Diff: 1
15) A
Diff: 2
16) D
Diff: 2
17) FALSE
Diff: 1
18) C
Diff: 1
19) A
Diff: 1
20) D
Diff: 1
21) A
Diff: 1
22) D
Diff: 1
23) E
Diff: 2
8