Clicker Questions for NEXUS/Physics Transverse waves on an
elastic spring
Slide 2
What happens when a a short pulse is flicked down a long, taut
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
Slide 3
What happens? NEXUS/Physics Clicker Questions
Slide 4
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?
1.Choice One 2.Choice Two 3.Choice Three 4.Choice Four y x Pulse
moving to the right 5. Choice Five 6. Choice Six 7. Choice Seven 8.
Choice Eight NEXUS/Physics Clicker Questions
Slide 5
Describing the motion of the beads Sketch vertical arrows
showing how each bead is moving as the pulse moves from the first
position to the second. y x Pulse moving to the right vyvy x
NEXUS/Physics Clicker Questions
Slide 6
A pulse is started on the string moving to the right. At a time
t 0 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. (x is horizontal and right, y is vertical and up) 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
Slide 7
A pulse is started on the string moving to the right. At a time
t 0 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. (x is horizontal and right, y is vertical and up) 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
Slide 8
A pulse is started on the string moving to the right. At a time
t 0 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. (x is horizontal and right, y is vertical and up) 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
Slide 9
A pulse is started on the string moving to the right. At a time
t 0 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. (x is horizontal and right, y is vertical and up) 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
Slide 10
What Controls the Speed of the Pulse on a Spring? To make the
pulse go to the wall faster 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
Slide 11
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. 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
Slide 12
Graph I Graph II Graph III Which goes with which? NEXUS/Physics
Clicker Questions
Slide 13
How do waves combine? We know how one pulse moves. What happens
when we get two pulses on top of each other? ? NEXUS/Physics
Clicker Questions
Slide 14
What happens if they overlap perfectly? ? NEXUS/Physics Clicker
Questions
Slide 15
What happens when they would have passed each other if the
other hadnt been there ? ? 1. 2. 3. 4. Other (Bounce off) (Pass
through) (Cancel) NEXUS/Physics Clicker Questions
Slide 16
? 1. 2. 3.Other NEXUS/Physics Clicker Questions
Slide 17
How about on the same side? ? NEXUS/Physics Clicker
Questions
Slide 18
Slide 19
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 the graph of
the vertical displacement of bead II as a function of time?
NEXUS/Physics Clicker Questions
Slide 20
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
Slide 21
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
Slide 22
Graph A is a graph of the string's shape and graph B is a graph
of the string's velocity. Is the wave on the string: A.a right
going traveling wave B.a left going traveling wave C.a part of a
standing wave growing in amplitude at time t 1 D.a part of a
standing wave shrinking in amplitude at time t 1 E.none of the
above F.you cant tell from the info given. NEXUS/Physics Clicker
Questions
Slide 23
Graph A is a graph of both the string's shape and the string's
velocity. Is the wave on the string: A.a right going traveling wave
B.a left going traveling wave C.a part of a standing wave growing
in amplitude at time t 1 D.a part of a standing wave shrinking in
amplitude at time t 1 E.none of the above F.you cant tell from the
info given. NEXUS/Physics Clicker Questions
Slide 24
Graph B is a graph of the string's shape and graph A is a graph
of the string's velocity. Is the wave on the string: A.a right
going traveling wave B.a left going traveling wave C.a part of a
standing wave growing in amplitude at time t 1 D.a part of a
standing wave shrinking in amplitude at time t 1 E.none of the
above F.you cant tell from the info given. NEXUS/Physics Clicker
Questions
Slide 25
This is the state of the PhET wave-on-a- string 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
Slide 26
For what frequencies will we generate a large (resonant)
standing wave if we drive it with a small amplitude? NEXUS/Physics
Clicker Questions
Slide 27
If we start our beaded string off in a sinusoidal shape y(x) =
A sin(x/L) it will oscillate with a frequency f 0. If we start it
out with a shape y(x) = A sin(2x/L) with what frequency will it
oscillate? A.f 0 B.2f 0 C.f 0 /2 D.Something else NEXUS/Physics
Clicker Questions
Slide 28
If we start our beaded string off in a sinusoidal shape y(x) =
A sin(x/L) it will oscillate with a frequency f 0. If we start it
out with a complex shape (shown) will it ever repeat itself? If
yes, with what frequency? A.No B.f 0 C.2f 0 D.f 0 /2 E.Something
else NEXUS/Physics Clicker Questions
Slide 29
In the figure below is shown a picture of a string at a time t
1. 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 t 1 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
Slide 30
In the figure below is shown a picture of a string at a time t
1. 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 t 1 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
Slide 31
In the figure below is shown a picture of a string at a time t
1. 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 t 1 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
