Presentation on theme: "Waves & Sound Part I - Characteristics of Waves Learning Goal SOL PS 8 – The student will investigate and understand characteristics of sound and technological."— Presentation transcript:
Waves & Sound Part I - Characteristics of Waves Learning Goal SOL PS 8 – The student will investigate and understand characteristics of sound and technological applications of sound waves.
Essential Questions What is a wave? What are the measurable properties of waves? How are wavelength, frequency, speed calculated?
A. What is a wave? Waves rhythmic disturbances that carry energy through matter or space (Video Clip)Video Clip Medium material through which a wave transfers energy solid, liquid, gas, or combination electromagnetic waves dont need a medium (e.g. visible light) Video Clip
A. What is a wave? Two Types: Longitudinal Transverse
A. What is a wave? Transverse Waves medium moves perpendicular to the direction of wave motion
A. What is a wave? Longitudinal Waves (a.k.a. compressional) medium moves in the same direction as wave motion
A. What is a wave? Wave Anatomy rarefaction compression wavelength Amount of compression corresponds to amount of energy AMPLITUDE.
B. What are the measurable parts of a wave? Your ideas?
B. What are the measurable properties of wave? Simulation: Waves on a StringWaves on a String Answer the following: 1) How does the amount that I wiggle the wrench affect the wave? 2) How does the speed that I wiggle affect the wave? 3) Switch to Oscillate: »What happens when I change amplitude? »What happens when I change frequency? »What happens when I change damping? »Explain these three underlined words.
B. What are the measurable parts of a wave? Wave Anatomy crests troughs wavelength amplitude corresponds to the amount of energy carried by the wave nodes
Frequency ( f ) # of waves passing a point in 1 second Hertz (Hz) shorter wavelength higher frequency higher energy 1 second B. What are the measurable parts of a wave?
C. How are wave properties calculated? Velocity ( v ) speed of a wave as it moves forward depends on wave type and medium v = × f v:velocity (m/s) :wavelength (m) f:frequency (Hz)
WORK: v = × f v = (3.2 m)(0.60 Hz) v = 1.92 m/s C. How are wave properties calculated? EX: Find the velocity of a wave in a wave pool if its wavelength is 3.2 m and its frequency is 0.60 Hz. GIVEN: v = ? = 3.2 m f = 0.60 Hz v f
WORK: f = v ÷ f = (5000 m/s) ÷ (417 m) f = 12 Hz C. How are wave properties calculated? EX: An earthquake produces a wave that has a wavelength of 417 m and travels at 5000 m/s. What is its frequency? GIVEN: = 417 m v = 5000 m/s f = ? v f
D. How do waves behave? Reflection occurs when a wave bounces back after striking a barrier.
D. How do waves behave? Refraction occurs when a wave bends as it passes from one medium to another.
D. How do waves behave? Video Clip: Wave InterferenceWave Interference
LETS REVIEW! (copy into notes) A wave is created when a source of ________ causes a vibration to move through a _________. There are several types of mechanical waves including _____________ waves and ____________ waves. Draw an example of each. energy medium transverse longitudinal
LETS REVIEW! (copy into notes) A _____________(compression) wave is a wave in which the vibration of the medium is ____________ to the direction in which the wave travels. This type of wave consists of a repeating pattern of _____________ and _____________. longitudinal parallel compressions rarefactions
LETS REVIEW! (copy into notes) All waves exhibit certain characteristics: __________, ___________, and ___________. Draw a transverse wave and label the three things listed above. Draw a longitudinal wave and label the three things listed above. wavelengthfrequency amplitude