P1 Homework 4
P1 The Earth in the Universe
Activity AP1.11.3 Calculations using the wave equation
Remember
wave speed
=
frequency  wavelength
(m/s)
(metre per second)
(Hz)
(m)
(hertz)
(metre)
To answer
1 A P-wave has a frequency of 0.5 Hz and a wavelength of 18
000 m. What is its wave speed?
2 An S-wave has a wavelength of 2000 m and a frequency of
2 Hz. What is its wave speed?
3 Which wave, the P-wave or the S-wave, would arrive at a
seismometer first after an earthquake? Why?
4 An earthquake deep underground emits seismic waves with
a frequency 2 Hz and a wavelength of 1300 m. Calculate the
wave speed.
5 A seismic wave has a frequency of 3 Hz.
(a) It has a wavelength of 1300 m. Calculate the speed of
the wave.
(b) The wave than passes into a rock where it travels more
quickly. The wavelength increases to 1500 m. Calculate
the speed of the wave in this new rock.
(c) Complete the sentences to describe the relationship
between the speed of a wave and the wavelength.
As the speed of the …………………………… the wavelength
……………………. The wavelength of the wave is ………………………….
to the speed.
We can also use the equation for different types of wave.
6 Some ocean waves have a wavelength of 150 m and arrive
once every 10 seconds – a frequency of 0.1 Hz. Calculate
the speed of the waves.
© University of York (UYSEG) and
the Nuffield Foundation
P1.11-7
This page may be copied solely for use
in the purchaser’s school or college
P1 The Earth in the Universe
Activity AP1.11.3 Calculations using the wave equation
7 Ripples on a pond have crests 10 cm apart. Eight waves
arrive at the bank every second.
(d) What is the wavelength of the water wave in metres?
(e) What is the frequency in Hz?
(f) Calculate the speed of the water waves in m/s.
8 Low rumbling thunder has a frequency of 80 Hz and a
wavelength of 4.25 m. Use these values to calculate the
speed of sound in air.
Optional
9 The humming noise made by a mosquito is its wings beating
600 times each second.
(a) What is the frequency of the hum?
(b) Use the speed of sound = 340 m/s to work out a value for
the wavelength.
10 The wavelength of a wave in a guitar string is 1.58 m and
the speed of the wave is 404 m/s. What is the frequency of
the note produced
11 The pitch of a sound depends on the frequency of the wave.
Look at the graph below. It shows the relationship between
the frequency and wavelength of 10 musical notes.
Use data from the graph to explain how the graph shows
that the wavelength in inversely proportional to the
frequency.
© University of York (UYSEG) and
the Nuffield Foundation
P1.11-8
This page may be copied solely for use
in the purchaser’s school or college