Topic 3.2: Wave Model Questions

A displacement-distance graph (a snapshot) and a displacement-time graph are drawn for the same wave.

Identify which quantity is read directly off each graph, and state the equation that combines them to give the wave speed.

Describe two properties that are shared by every wave in the electromagnetic spectrum, from radio waves to gamma rays.

Identify whether each of the following waves is transverse or longitudinal: (i) a sound wave in air; (ii) visible light; (iii) a wave sent along a stretched spring by pushing and pulling one end along its length.

State the difference between a transverse wave and a longitudinal wave in terms of how the particles of the medium move relative to the direction the wave travels.

An FM radio station broadcasts at a frequency of 96 MHz.

Electromagnetic waves travel through air at 3.0 × 10⁸ m s⁻¹.

Calculate the wavelength of these radio waves.

An FM radio station broadcasts at a frequency of 100 MHz.

Using c = 3.00 × 10⁸ m s⁻¹, calculate the wavelength of the radio wave.

A loudspeaker emits a sound wave whose plane wavefronts are drawn 0.85 m apart.

Determine the wavelength of the sound and outline what the spacing between neighbouring wavefronts tells you.

State whether electromagnetic waves are transverse or longitudinal.

A wave is drawn using both wavefronts and a ray.

Identify how the ray is oriented relative to the wavefronts.

On a wave diagram, state what a single wavefront represents.

State the wave equation that relates the speed v of a wave to its frequency f and wavelength λ.

Outline the difference between a wavefront and a ray when used to represent a wave.

A microwave oven produces electromagnetic waves of wavelength 0.12 m.

Electromagnetic waves travel at 3.0 × 10⁸ m s⁻¹.

Determine the frequency of these microwaves.

A transverse water wave travels to the right.

A snapshot of the surface shows the displacement repeating every 2.4 m, and a float bobbing on the surface completes 2.5 full up-and-down cycles every second.

Determine the wavelength and the speed of the wave.

A loudspeaker emits a sound wave that travels horizontally across a room.

As the wave passes, the air molecules vibrate horizontally, back and forth along the same line as the wave moves.

State whether the wave is transverse or longitudinal, name the two types of region it produces in the air, and explain why sound cannot be transverse in a gas.

A transverse wave travels to the right along a string.

A snapshot (displacement–distance graph) shows the pattern repeating every 0.80 m with a maximum displacement of 2.0 cm.

A separate displacement–time graph of one point on the string repeats every 0.40 s.

Determine the wavelength, amplitude and wave speed, and state how a particle on the string moves relative to the wave's direction of travel.

A buoy bobbing on the sea takes 4.0 s to complete one full up-and-down cycle, and successive wave crests are observed to be 6.0 m apart.

Calculate

A snapshot of straight, parallel wavefronts on the surface of water shows them at 0.30 m, 0.70 m and 1.10 m measured along a ray from the wave source.

The source dips at 6.0 Hz.

Calculate the wavelength and the speed of the water wave, and state what the spacing between the wavefronts represents.

A dermatology clinic uses an ultraviolet lamp to treat a skin condition. A student is asked to describe the radiation the lamp emits.

Which row correctly gives an approximate frequency of the ultraviolet light AND the type of wave that all electromagnetic radiation is?

A transverse wave travels along a stretched string in the positive x-direction.

The graph shows the displacement y of the string against distance x at one instant.

The wave has a period of 0.20 s.

What is the average speed of a single particle of the string during one complete oscillation?

[Diagram: x-axis from 0 to 8 label x, y-axis from -4 to 4 label y, polyline: (0,0)-(1,4)-(2,0)-(3,-4)-(4,0)-(5,4)-(6,0)-(7,-4)-(8,0) "y/cm vs x/cm"]