Phyics Unit 4 Test Review Flashcards
able to identify parts/characteristics of a wave: crest, trough, rest position, amplitude, wavelength, number of cycles, etc…
-Be able to complete calculations for period and frequency, speed of a wave from the universal wave equation or the speed of a sound wave at a specific temperature.
-Know the 2 different wave types (longitudinal and transverse), the direction of wave travel and the direction of particle vibration
longitudinal: direction of wave is parallel to motion. ex. sound
transverse: direction of wave is perpendicular. ex. light
-Know definitions for a vibration/oscillation, mechanical wave, phase and phase shift
vibration: …
-mechanical wave: disturbance that transfers over a distance
-phase & phase shift: the x co-ordinate of a specific point on wave along the x-axis with respect to another identical wave
-What type of wave is a sound wave? What are compressions and rarefactions? What is sound and how it is produced?
-sound waves are longitudinal waves.
-compressions: area where particles are close together
-rarefactions: region in longitudinal wave where particles are further apart than normal
-sound is a form of energy produced by rapid vibrating of objects, that can be heard by the human air
-What factors affect the speed of a sound wave in air? In a string?
in air:
-depends on temperature and the properties of the material
-the stiffer the material, the faster the speed of sound
…..
-What is mach number? What are the names for different values of mach and complete mach calculations.
-used when aircrafts travel at speed comparable to the speed of sound
-ratio of speed of an object to the speed of sound in air
different value of mach
-mach 1: speed of sound at a given temperature
-subsonic speed: less than mach 1
-supersonic speed: greater than mass 1
-hypersonic speed- greater than or equal to mach 5
-What is interference? What are the 2 interference types? When do they occurs?
-when 2 or more waves act simultaneously on the same particles of a medium
-constructive: waves build each other up (larger amp). and destructive: waves diminish each other (smaller amp)
-Be able to draw a resulting interference wave form/
add amps
-What are beats? How do they occur? Calculate beat frequency.
-beats: pulsating sound in which the intensity alternated between loud and soft at a specific frequency
-occur when 2 waves of slightly different frequency are emitted together, a complicated wave is created
-What are fixed and free end reflections and what is the resulting wave form for each? -What happens when a wave travels between mediums (materials) of different densities? What characteristics of the wave change and which stay the same when this happens?
-fixed: reflection from rigid obstacle, pulse is inverted, phase shift
-free: reflection where new medium is free to move, pulse is not inverted
-some energy is transmitted into new medium, some is reflected
-particles of the slower medium have greater inertia
-waves change speed = change in wavelength
-frequency will remain the same (is dependent on source)
-What is a standing wave? Solve standing wave problems in stringed instruments or instruments that are air columns.
standing wave: interference pattern when an in coming and reflected wave interfere, effect is a wave pattern that seem stationary
-occurs between fixed ends
-are charactered by notes and antinodes
-What is resonance? Why is it important to consider when building a structure?
resonance: increase in amplitude and vibration of a mechanical system exposed to periodic force whose frequency is very close or equal to the natural frequency of the system
-is important because ….
-What is damping? How is it useful?
reduction in amplitude of wave as a result of energy absorption or destructive interference
-useful because…
-Explain the doppler effect and solve associated problems.
