Clicker Questions for NEXUS/Physics
Transverse waves
on an elastic spring
A. It keeps its shape but gets smaller
the farther it goes.
B. It keeps its shape and stays the same size.
C. It changes shape, but stays about the same
size.
D. It changes shape, and gets smaller.
E. I have no clue.
NEXUS/Physics Clicker Questions
What happens when a
a short pulse is “flicked”
down a long, taut spring?
NEXUS/Physics Clicker Questions
What happens?
If this is the space-graph (photo at an instant
of time) what does the time-graph look like
for the bead marked with a red arrow?
x
1.
2.
3.
4.
Choice One
Choice Two
Choice Three
Choice Four
5.
6.
7.
8.
Choice Five
Choice Six
Choice Seven
Choice Eight
NEXUS/Physics Clicker Questions
y
Pulse moving to the right
Describing the motion
of the beads
Pulse moving to the right
x
vy
• Sketch vertical arrows showing
how each bead is moving as
the pulse moves from the first
position to the second.
x
NEXUS/Physics Clicker Questions
y
A pulse is started on the string moving to the
right. At a time t0 a photograph of the string
would look like figure 1 below. A point on the string
to the right of the pulse is marked by a spot of paint.
Which graph would look most like a graph of the
y displacement of the spot as a function of time?
7 None of these
NEXUS/Physics Clicker Questions
(x is horizontal and right, y is vertical and up)
A pulse is started on the string moving to the
right. At a time t0 a photograph of the string
would look like figure 1 below. A point on the string
to the right of the pulse is marked by a spot of paint.
Which graph would look most like a graph of the
x velocity of the spot as a function of time?
7 None of these
NEXUS/Physics Clicker Questions
(x is horizontal and right, y is vertical and up)
A pulse is started on the string moving to the
right. At a time t0 a photograph of the string
would look like figure 1 below. A point on the string
to the right of the pulse is marked by a spot of paint.
Which graph would look most like a graph of the
y velocity of the spot as a function of time?
7 None of these
NEXUS/Physics Clicker Questions
(x is horizontal and right, y is vertical and up)
A pulse is started on the string moving to the
right. At a time t0 a photograph of the string
would look like figure 1 below. A point on the string
to the right of the pulse is marked by a spot of paint.
Which graph would look most like a graph of the
y force on the spot as a function of time?
7 None of these
NEXUS/Physics Clicker Questions
(x is horizontal and right, y is vertical and up)
What Controls the Speed of the Pulse
on a Spring?
A. Move your hand up and down more quickly
(but by the same amount).
B. Move your hand up and down more slowly
(but by the same amount).
C. Move your hand up and down a larger distance in the same time.
D. Move your hand up and down a smaller distance in the same time.
E. Use a heavier string of the same length under the same tension.
F. Use a string of the same density but decrease the tension.
G. Use a string of the same density but increase the tension.
H. Put more force into the wave,
I. Put less force into the wave.
NEXUS/Physics Clicker Questions
To make the pulse go to the wall faster
Three pieces of tape are attached to the
spring. They are marked by small circles in the
figure and are labeled A , B , and C .
Graph the velocity
of each of the 3 pieces
of tape as the pulse
moves past them.
(Take this instant as t = 0)
NEXUS/Physics Clicker Questions
Below is a snapshot of a piece of an elastic spring
on which a pulse is traveling. Each square of the
grid represents 1 cm. In a video of the motion of
the pulse, the pulse is observed to move a
distance of 2 cm in 0.04 seconds.
Which goes
with which?
Graph I
2. y = f (x - d)
3. y = f (x) + d
4. y = f (x) - d
5. You can't tell if you don't
know the form of f .
6. You can't tell for some
other reason.
Graph II
Graph III
NEXUS/Physics Clicker Questions
1. y = f (x + d)
How do waves combine?
?
NEXUS/Physics Clicker Questions
We know how one pulse moves.
What happens when we get two
pulses on top of each other?
?
NEXUS/Physics Clicker Questions
What happens
if they overlap perfectly?
What happens when they would have passed
each other if the other hadn’t been there?
1.
(Bounce off)
2.
(Pass through)
3.
(Cancel)
4.
Other
NEXUS/Physics Clicker Questions
?
1.
2.
3.
NEXUS/Physics Clicker Questions
?
Other
?
NEXUS/Physics Clicker Questions
How about on the same side?
NEXUS/Physics Clicker Questions
Which of the graphs could
serve as the graph of the
vertical displacement of
bead II as a function of time?
NEXUS/Physics Clicker Questions
An elastic string (modeled as a series of beads) driven by a
wheel driving one of the beads up and down sinusoidally. .
The driving wheel has generated a traveling wave of amplitude
10 cm moving to the right. (The string continues on for a long
way to the right as indicated by its going “out the window.”) The
figure shows t = 0, when the green bead marked “II” is passing
through its equilibrium point.
Which of the graphs could
serve as a graph of the
vertical displacement of
bead III as a function of time?
NEXUS/Physics Clicker Questions
An elastic string (modeled as a series of beads) driven by a
wheel driving one of the beads up and down sinusoidally. .
The driving wheel has generated a traveling wave of amplitude
10 cm moving to the right. (The string continues on for a long
way to the right as indicated by its going “out the window.”) The
figure shows t = 0, when the green bead marked “II” is passing
through its equilibrium point.
Which of the graphs could serve
as a graph of the vertical
displacement of the elastic
string at the time t = 0 as a
function of position?
NEXUS/Physics Clicker Questions
An elastic string (modeled as a series of beads) driven by a
wheel driving one of the beads up and down sinusoidally. .
The driving wheel has generated a traveling wave of amplitude
10 cm moving to the right. (The string continues on for a long
way to the right as indicated by its going “out the window.”) The
figure shows t = 0, when the green bead marked “II” is passing
through its equilibrium point.
Graph A is a graph of the string's shape and
graph B is a graph of the string's velocity. Is the
A.
B.
C.
D.
E.
F.
a right going traveling wave
a left going traveling wave
a part of a standing wave growing in amplitude at time t1
a part of a standing wave shrinking in amplitude at time t1
none of the above
you can’t tell from the info given.
NEXUS/Physics Clicker Questions
wave on the string:
Graph A is a graph of both the string's shape
and the string's velocity. Is the wave on the
A.
B.
C.
D.
E.
F.
a right going traveling wave
a left going traveling wave
a part of a standing wave growing in amplitude at time t1
a part of a standing wave shrinking in amplitude at time t1
none of the above
you can’t tell from the info given.
NEXUS/Physics Clicker Questions
string:
Graph B is a graph of the string's shape and
graph A is a graph of the string's velocity. Is the
A.
B.
C.
D.
E.
F.
a right going traveling wave
a left going traveling wave
a part of a standing wave growing in amplitude at time t1
a part of a standing wave shrinking in amplitude at time t1
none of the above
you can’t tell from the info given.
NEXUS/Physics Clicker Questions
wave on the string:
NEXUS/Physics Clicker Questions
This is the state of the PhET wave-on-astring simulation when the string is very
long so reflection can be ignored.
What is the speed of the wave (assuming
that the frequency is given in cycles/min?
NEXUS/Physics Clicker Questions
For what frequencies will we generate
a large (resonant) standing wave
if we drive it with a small amplitude?
A. f0
B. 2f0
C. f0/2
D. Something else
NEXUS/Physics Clicker Questions
If we start our beaded string off
in a sinusoidal shape
y(x) = A sin(πx/L)
it will oscillate with a frequency f0.
If we start it out with a shape
y(x) = A sin(2πx/L)
with what frequency will it oscillate?
A.
B.
C.
D.
E.
No
f0
2f0
f0/2
Something else
NEXUS/Physics Clicker Questions
If we start our beaded string off
in a sinusoidal shape
y(x) = A sin(πx/L)
it will oscillate with a frequency f0.
If we start it out with a complex shape
(shown) will it ever repeat itself?
If yes, with what frequency?
A.Left traveling wave
B.Right traveling wave
C.A standing wave increasing
in amplitude
D.A standing wave decreasing
in amplitude
E.None of these.
NEXUS/Physics Clicker Questions
In the figure below is shown a picture of a string at a time
t1. The pieces of the string are each moving with velocities
indicated by arrows. (Vertical displacements are small and
don't show up in the picture.) if the shape of the string at time
t1 is that shown below (displacement magnified by X100)
then the motion of the string is
A.Left traveling wave
B.Right traveling wave
C.A standing wave increasing
in amplitude
D.A standing wave decreasing
in amplitude
E.None of these.
NEXUS/Physics Clicker Questions
In the figure below is shown a picture of a string at a time
t1. The pieces of the string are each moving with velocities
indicated by arrows. (Vertical displacements are small and
don't show up in the picture.) if the shape of the string at time
t1 is that shown below (displacement magnified by X100)
then the motion of the string is
A.Left traveling wave
B.Right traveling wave
C.A standing wave increasing
in amplitude
D.A standing wave decreasing
in amplitude
E.None of these.
NEXUS/Physics Clicker Questions
In the figure below is shown a picture of a string at a time
t1. The pieces of the string are each moving with velocities
indicated by arrows. (Vertical displacements are small and
don't show up in the picture.) if the shape of the string at time
t1 is that shown below (displacement magnified by X100)
then the motion of the string is