Y10 Wave Calculations I

Which of these Waves are Transverse and which are Longitudinal?

Groups:

(a) Transverse

,

(b) Longitudinal

• Slinky vibrating along the spring

• Water Wave

• Slinky vibrating perpendicular to the way the wave is travelling

• Electromagnetic Wave e.g. light, radio, microwave, X-rays

• Mexican Wave

• Sound Wave

A diagram of a transverse wave is shown.

Select the point that represents the wavelength of the wave.

A diagram of a transverse wave is shown.

Select the point that represents the amplitude of the wave.

A wave has a frequency of 250 kHz. What is its period?

• 0.004 s

• 4 x 10^-6 s

• 4.0 s

• 0.0004 s

Answer explanation

250 kHz = 250,000 Hz

period = 1 / frequency = 1 / 250,000 = 4 x 10^-6 s

You are on a boat and notice that 5 wave crests (the peak of a wave) pass by your boat every minute.

What is the frequency of the water waves passing by your boat?

• 0.083 Hz

• 5.0 Hz

• 12 Hz

• 0.20 Hz

Answer explanation

5 waves per minute would be 5 waves every 60s.

To find the number of waves in one second (the frequency), then you need to divide 5 by 60s to get 0.083 Hz.

Capital FM radio operates radio waves at a frequency of 95.8 MHz.

What is the wavelength of a capital FM radio wave?

Speed of light (and all electromagnetic waves) = 3 x 10^8 m/s

• 3.13 m

• 0.313 m

• 3,130,000 m

• 3,130 m

Middle C on a piano is at 261.63 Hz. This is created by a string inside the piano vibrating.

The speed of sound across the middle C string of a piano is 360 m/s.

The length of the string is HALF the wavelength of the sound wave. How long is the string?

• 0.69 m

• 0.36 m

• 0.72 m

• 1.38 m

On the Hertzsprung-Russell diagram, which region represents the Main Sequence stars?

On the Hertzsprung-Russell diagram, which region represents the Red Giant stars?

On the Hertzsprung-Russell diagram, which region represents the Red Supergiant stars?