Waves travel through a wave tank. A small bob on the surface of the water is attached to an elastic rope which is fixed to the base of the tank.


The graph below shows the variation of vertical displacement of the bob with time.

1.Use the figure and the graph above to determine:
（1）the frequency of the water wave. f =    Hz
（2）the speed of the water wave. v =    $m\,s^{-1}$
2.State two times when the bob is at a crest of the water wave and two times when the bob is at the trough of the water wave.

  Water drips onto a pond every 3.0 seconds. The speed of water waves in the pond yp) qk.- zucvkz w5r40qc pvzkw0yz5- k4r)u.has been measured to be $1.2\,ms^{−1}$. What is the wavelength of water waves generated because of the drops?

  A longitudinal wave is travelling in a medium from left to right. The diagram below is a snapshot of plane wave fronts of showing position of particles X (center of compression) and Y (center of rarefaction) in the medium at t=0 s.


1.Distinguish between a transverse wave and a longitudinal wave.
2.In the graph below, the solid line shows the variation of displacement s of particle X with time, and the dotted line shows the variation of displacement of particle Y with time.

(1)Show that the angular frequency $ω$ of the oscillating particles in the medium is 3.9 $rad s^{−1}$.
(2)Calculate the speed of the wave in the medium. v =    $cm\,s^{-1}$
3.(1)State the phase difference between particles X and Y.   
(2)Determine the speed of particle Y when t=2.3 s. v =    $mm\,s^{-1}$

  A traveling wave is generated on a string tied to a speaker as shown.


Which of the following statements are correct about the travelling wave?

I. If the frequency of the sound decreases, the wavelength of the travelling wave increases.
II. If the speaker emits a louder sound the amplitude of the travelling wave increases.
III. If the frequency of the sound increases, the travelling wave moves along the string faster.

  For a wave traveling in a medium, the variation of the particles' displ1 e2bk 2o0fvtpl ldgq.l,(fm5 acement with distance travelled is shown in the following graphs, which represent the wave at differenb(,52lplmg.1f etfok02dl vq t moments in time of a wave travelling to the right.


Graph I shows the wave at t=0s, while graph II is at t=1s.
The time difference between the two graphs is less than the wave's period.
Graph I


Graph II

What is the wave speed?

  A radio wave of frequency 90 Hz travels a d ig/bq00wvef. uamr m-9)vlx7 istance $d$. The number of wavelengths that can fit into this distance is 6000. What is $d$?

  A student uses the shown setup to measure the speed of sound.



The sound source has a frequency of $590\,Hz$. The student changes the distance between the two microphones d and records the time difference $Δt$ between the received sounds from the microphones.
The graph below shows the data from this experiment.



1.Draw the line of best fit.
2.Determine the fractional uncertainty of d when the time difference Δt is 2.2 ms.fractional unceratinty =   
3.Showing your working on the graph, calculate the speed of the sound wave. c =    $ms^{-1}$
4.Determine the wavelength of the sound. λ =    m

  A boy tied two identical ropes to a fixed wall for a fitness exercise. He shakes the ropes to form waves.


A point on the right rope oscillates with a period of 0.4s. A point on the left rope oscillates with a period of 0.2s.
What is the ratio $\frac{wavelength of right rope}{wavelength of left rope}$

  A vibration generator with a frequrw ;12(tk m4zpn(om;mqg c/mbency of 5Hz produces a travelling wave in a string. The graph shows how displacement of particles in the string var m2(r /;k( omtwb4qn;mzpmcg 1ies with the distance from the source.


What is the wavelength and the speed of the wave?

  A wave travels on a rope as showwddg:db0mz4 9n, where $P$ is a point on the rope halfway between the equilibrium position and the maximum displacement.


Which is correct about the direction and magnitude of the velocity of point $P$ after half a period compared to the shown position?

  A longitudinal wave travels through a medium from left to right. Graph 1 below shows how the displacement $x$ of a particle $P$ in the medium varies with time. Positive displacement is to the right.


1.Describe what is meant by a longitudinal wave.
2.Use the graph to determine:
(1)the amplitude of the wave    mm
(2)the frequency of the wave f =    Hz
(3)the direction of motion of the particle at $t=10ms$.
3.Graph 2 below shows variations of displacement of particles in the medium with distance from the source of wave at an instant in time.

(1)Use the graph to calculate the speed of the wave. State an appropriate unit for your answer. v =    $ms^{-1}$
(2)Label with the letter C a position on the graph at the center of a compression, and a letter R at the center of a rarefaction.
Graph 1 showing the displacement of particle P with time is reproduced below.

A second source is added to the medium that generates identical waves $14\,cm$ closer to $P$ than the original source.
4.Draw a second dotted line to show how the displacement, $x$ of a particle in the medium would vary with time due solely to the second source.

  A longitudinal wave is travelling in a medium from left to right. The graph shows the variation of the displacement of the particles of this medium with distance along the medium $x$.


Which point on the graph is at the center of a rarefaction? Displacements to the right of equilibrium positions are positive.

  A speaker produces a sound wave in a gas. The graph shows the variation of the gas particles' displacement from equilibrium with distance.


Which of the following shows this variation when the sound wave travels in a solid?