Question

grade 7_sound waves properties
part i. drag and drop.
crest amplitude trough wavelength
amplitude wavelength rarefaction compression

Explanation:

• For the first wave diagram (transverse wave):
• The vertical distance from the rest position (AC line) to the crest (B) is the amplitude.
• The highest point (F) is the crest.
• The lowest point (D) is the trough.
• The horizontal distance (EG) related to one - full wave cycle (if considering from a similar point on the next wave) would be the wavelength (but in the given labels, the box near B is amplitude, near F is crest, near D is trough).
• For the second wave diagram (longitudinal wave):
• The region where the coils are close together is compression.
• The region where the coils are spread apart is rarefaction.
• The horizontal distance for one full cycle (related to the repeating pattern) is wavelength.
• The maximum displacement from the rest position (vertical arrow) is amplitude.

Answer:

• First diagram (top):
• Box near B: Amplitude
• Box near F: Crest
• Box near D: Trough
• Second diagram (bottom):
• Long horizontal arrow: Wavelength
• Vertical arrow: Amplitude
• Region with closely - packed coils: Compression
• Region with spread - out coils: Rarefaction