Topic 3.2: Wave Model Questions

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.

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

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.

State whether electromagnetic waves are transverse or longitudinal.

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.

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

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

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.

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.

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.

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

A wave is drawn using both wavefronts and a ray.

Identify how the ray is oriented relative to the wavefronts.

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 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 loudspeaker emits a steady musical note of frequency 256 Hz into air, where the speed of sound is 340 m s⁻¹.

Calculate the wavelength of the sound wave, and state how the wavelength would change if the same speaker played a higher-pitched note at the same speed of sound.

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"]

Describe how a longitudinal wave travelling through a gas produces regions of high and low pressure, and name those two types of region.

A particle on a transverse wave oscillates with an amplitude of 5.0 cm and a period of 0.25 s.

Estimate the average speed of the particle over one complete cycle.

A student claims: 'Gamma rays travel faster than radio waves in a vacuum because they carry more energy.' Explain whether the student is correct, referring to the speed of EM waves in a vacuum.