Waves Rhythmic disturbance that carries energy through matter or space
Types of Waves Transverse- wave travels perpendicular to motion of the disturbance
Types of Waves Longitudinal- wave travels in the same direction or parallel to the direction of the disturbance
Electromagnetic Waves Do not need a medium to travel All travel at the speed of light c = 3.0 x 10 8 m/s
Properties Wavelength (λ) - the distance between 2 identical spots on a wave Amplitude- from equilibrium to crest or trough Crests- highest point Troughs- lowest point Period (T)- time (s) measured for one wavelength Frequency (Hz)- # of complete oscillations in one second
Wave Velocity v = λf f = 1/T
Practice Problems A wave has a frequency of 262 Hz and a wavelength of 1.29 m. What is the speed of the wave? How long will it take the wave to travel 91.4 m? What is the period of the wave?
The frequency of violet light is 7.5 x hertz. What is its wavelength? What is its period?
A wave with a wavelength of 2.5 meters travels through a certain point 6 times per second. What is the velocity of the wave?
Wave Behavior Waves can cross mediums at a boundary Incident wave- strikes the boundary Reflected wave- returning wave When the wave hits the boundary, some energy is reflected back as it moves into the new medium
Interference Two or more waves interact with each other
Constructive- wave displacements are in the same direction
Destructive- when two waves of opposite amplitudes meet
Standing Wave Combination of interference Wave appears to be standing still Increasing frequency produces more nodes (points of destructive interference) and antinodes (points of destructive interference)