P4.2 PROPERTIES OF WAVES, INCLUDING LIGHT AND SOUND

Question 1

Angle of incidence is……….

Answer 1

the angle between the INCIDENT LIGHT RAY and the normal to the surface.

Question 2

Angle of reflection is……….

Answer 2

the angle between the REFLECTED LIGHT RAY and the normal to the surface inside the material.

Question 3

light waves …………..when they travel from air into glass

Answer 3

slow down

Question 4

angle of incidence ……………..angle of reflection

Answer 4

equal to

Question 5

sound wave require …………… to travel through.

Answer 5

a medium

Question 6

reflection of a sound wave is called……..

Answer 6

echo

Question 7

longitudinal wave consists of ………. and …………..

Answer 7

compression and rarefractions

Question 8

A compression is ………..

Answer 8

a place where the molecules are bunched together

Question 9

A rarefaction is ………..

Answer 9

a place where the molecules are spread out

Question 10

Humans can hear sounds between about……… and ……………… in frequency (although this range decreases with age).

Answer 10

20 Hz and 20 000 Hz

Question 11

Ultrasound is ……………………

Answer 11

the name given to sound waves with a frequency greater than 20 000 Hz.

Question 12

light are ……………wave

Answer 12

transverse

Question 13

Sound waves can be reflected when they travel through balloons filled with gases.
How would the motion of a sound wave be changed if it traveled through a balloon filled with carbon dioxide?

Answer 13

Being more dense than air, the carbon dioxide in the balloon will SLOW DOWN the sound wave.
This will tend to FOCUS the sound TOGETHER, like a lens.
( a balloon filled with HYDROGEN will do the OPPOSITE ).