p ar
t
of a
How does it work?
When you speak or shout, or even clap your hands, the vibrations go out in all
directions through the air as waves. When the waves reach our ears, they make our
eardrums vibrate so that we can hear sound. To get to our ears, sound waves need
to travel through some stuff, like air, that can vibrate. Air is made up of particles,
and these are what move to make the sound waves. The vibrating object, like your
vocal chords, bumps the air particles next to it. They then bump the particles
next to them, and so on.
In spac
e no on
e can h
In outer space, there are no particles to bump into, so sounds can't travel.
ear you
scream
.
No particles means no vibrations, and no vibrations means no sound waves,
which means no sound!
‘IN SPACE NO ONE CAN HEAR YOU SCREAM’ is a quotation from which Hollywood Film?
The theremin is a musical instrument
invented in 1927 by Russian scientist Leon
Theremin, and is played without physical
contact! The thereminist stands in front of
the instrument and moves their hands near
to two metal antennae. The distance from
one antenna determines frequency (pitch)
and the distance from the other controls
amplitude (volume). Higher notes are played
by moving the hand closer to the pitch
antenna. Louder notes
are played by moving the
hand away from the
volume antenna. Usually,
the right hand controls the
pitch and the left controls
the volume, although some
performers reverse this.
Watch Leon Theremin
playing his own
instrument on YouTube.
More modern versions of
the same instrument are
called a MOOG!
Science Technology Engineering Maths
Tim
Did you know?
Think!
o
tWhat simple tests could you carry out to
e show that sound waves can also travel
through water, wood and metal?
How do other musical instruments create
sound? Compare a guitar, flute, trombone,
and drum.
How do you know that the human body can
act as a natural CAPACITOR and hold an
electrical charge?
Explore how Theremin’s invention was
originally devised as a proximity sensors
spying device in 1920’s Russia.
For more resources like this,
this visit
visitww.baesystemseducationprogramme.com/resources
www.baesystemseducationprogramme.com/resources
te a c hin g
SOUND WAVES
Things you’ll need: What to do:
Using a tin opener, remove both ends of a tin, carefully removing any sharp
Empty tin
edges. Cut the balloon so that it has a large, flat surface area and stretch the
Tin opener
balloon around one end of the tin. Secure the balloon with the rubber band.
Large balloon
Glue a small mirror to the centre of the stretched balloon, the reflective side
Torch
facing up. Place the tin on its side on a table and secure it so that it doesn't
Small mirror
roll away. Turn the lights out and shine the torch onto the mirror at an angle
so that the light bounces off the mirror and reflects on the wall.
Scissors
Clap your hands next to the open end of the soup can. What happens to the
Rubber band
reflection on the wall? Then shout into the open end of the can.
Glue
What happens?
5
k
KS3
pac
TOPIC:
Investigating Sound Waves