1. Wave Properties

2. Waves Wave = a disturbance that propagates
through a material medium or space.
A mechanical wave needs a medium
An electromagnetic wave can travel through a vacuum (empty space)
Medium = a substance or material that carries the wave.
rope wave
medium: rope
stadium wave
medium: people
water wave
medium: water

3. Waves transfer energy Waves not particles
The interactions of one particle of the medium with the next adjacent particle allow the disturbance to travel through the medium.
Mechanical Energy
Electrical Energy
Mechanical Energy

4. Pulse Wave: Periodic Wave: Single disturbance in a medium
Repeated disturbance in a medium

6. Transverse Wave Longitudinal Wave
Displacement of the wave is perpendicular to
the motion of the wave.
Longitudinal Wave
Displacement of the wave is parallel to
the motion of the wave.

7. Wave Characteristics Displacement vs. Time Graph crest
wavelength = distance it takes for wave to repeat itself
period = time it takes for wave to repeat itself
crest
amplitude
displacement (m)
time (s)
trough
frequency = #cycles per second
midline = equilibrium position

8. the maximum displacement
Amplitude
the maximum displacement
from equilibrium
Units: meters

9. The distance it takes for a wave to repeat itself
Wavelength (λ)
The distance it takes for a wave to repeat itself
Units: meters

10. Frequency (f) - the number of vibrations per second
Units: Hz
Period (T) – the time interval it takes for the wave to repeat itself
Units: seconds

11. Wave Speed (v) - speed of the wave
Units: m/s
Speed of a wave depends on the medium.
Speed increases as the density of the medium increases

12. In which medium will a wave travel the fastest?
In which medium will a wave travel the slowest?
Air
Water
Metal table

13. In which medium will a wave travel the fastest?
In which medium will a wave travel the slowest?
Air
Water
Metal table
slowest
fastest

14. result of two waves with the same wavelength, frequency, and amplitude
A standing wave is the
result of two waves with the same
wavelength, frequency, and amplitude
traveling in opposite directions
through the same medium.

16. Example 1 𝑣=λ𝑓 𝑣=(4.7 𝑚)(3 𝐻𝑧) 𝑣=14.1 𝑚/𝑠
A standing wave travels through rope. You measure the distance from crest to crest to be 4.7 m and the crest and the wave repeats itself 3 times per second. What is the speed of the wave in the rope?
𝑣=λ𝑓
𝑣=(4.7 𝑚)(3 𝐻𝑧)
𝑣=14.1 𝑚/𝑠

17. Example 2
It takes a wave 7.5 s to complete a single vibration. If the wave travels at a speed of 120 m/s, what is its wavelength?
𝑣=λ𝑓
𝑓= 1 𝑇
𝑓= 𝑠
𝑓= Hz
𝑣=(120 𝑚)( 𝐻𝑧)
𝑣=16 𝑚/𝑠