The document discusses wave properties including frequency, period, and interactions with surfaces. It defines frequency as the velocity divided by wavelength and calculates the frequency of a wave moving at 5 m/s with a wavelength of 1 m as 5 cycles/sec and a period of 0.2 sec. It also lists the four interactions waves can have with surfaces as reflection, refraction, diffraction, and absorption.

20. Frequency =?
Period =?
λ= 1 m
s = 5 m/s
f = s ÷ λ
f = 1/T or T = 1/f

21. Frequency:
f = velocity ÷ wave length
f = 5 m/s ÷1 m
f= 5 cycles/sec
Time period:
T=1/f
T = 1/5 cycles/s
T = .2 sec

22. When a wave encounters a
surface, four interactions can
occur:
 Reflection,
 Refraction,
 Diffraction, or
 Absorption.

26. • The oscillations of a transverse wave are not in
the direction the wave moves.

29. • The oscillations of a longitudinal wave are in
the same direction that the wave moves.

36. • What happens when one pulse is on top of the
string and the other is on the bottom?
• When the pulses meet in the middle, they
cancel each other out.
• During destructive interference, waves add up
to make a wave with smaller or zero amplitude.