General properties of waves

Question 1

waves transfer____ without transferring _____

Answer 1

energy

matter

Question 2

what are mechanical waves? name 2 examples

Answer 2

these are waves that need a substance to travel through such as: sound waves, water waves, seismic

Question 3

what are electromagnetic waves? name 2 examples

Answer 3

these are waves that can travel through a vacuum like microwaves, radio waves, light waves

Question 4

what are transverse waves

Answer 4

waves whose oscillations are perpendicular to energy transfer

Question 5

what are longitudinal waves

Answer 5

waves whose oscillations are parallel to energy transfer

Question 6

name 2 differences between transverse and longitudinal waves

Answer 6

1. transverse waves oscillations are perpendicular to energy transfer meanwhile longitudinal waves oscillations are parallel to energy transfer
2. transverse waves have peaks and troughs, longitudinal waves have compressions and rarefaction

Question 7

what is the:
amplitude of the wave?
wavelength?
frequency?
period?

Answer 7

• height of the wave (m)
• distance from peak to peak (m)
• number of waves or vibrations per second (Hz)
• time taken for a single vibration (s)

Question 8

what are the 4 things waves can do?

Answer 8

• reflect
• refract
• transmit
• defract

Question 9

in reflection what angles are equal

Answer 9

the angle of incidence and angle of reflection

Question 10

what is specular reflection

Answer 10

• reflection that takes place on a smooth surface, clear image and rays are parallel after reflection

Question 11

what is diffuse reflection

Answer 11

-reflection on unsmooth surfaces its an unclear image and rays are not parallel

Question 12

what is refraction?

Answer 12

a change in density means the wave changes speed causing it to change direction

Question 13

where will the wave bend if it gets:
faster?
slower

FAST

Answer 13

• faster means it bends away from the normal
• slower means it bends towards the normal

Far Away Slow Towards

Question 14

why does refraction occur?

Answer 14

because the wave enters at an angle, parts of the wave slows down before the rest causing it to bend

Question 15

what is diffraction?

Answer 15

this is the spreading of waves when passing through a gap or close to an obstacle

Question 16

how is diffraction affected when the wavelength is comparable to the size of the gap (the gap is a lot smaller than the wavelength)

Answer 16

lots of diffraction happens

Question 17

how is diffraction affected when the wavelength is similar to the size of the gap (the gap is a similar to the wavelength)

Answer 17

less diffraction occurs

Question 18

diffraction happens around obstacles

why is the signal affected in hilly areas?

Answer 18

radio waves diffract around large mountains and don’t spread enough behind the hill, weakening signal