Properties of waves Flashcards
What is a wave?
- vibration about an undisturbed position
- transfers energy and information from one place to another
What are mechanical waves?
- transfer energy through a medium
- vibrations of particles
What are electromagnetic waves?
- oscillations of electrical and magnetic fields
What are transverse waves?
- particles vibrate up and down on fixed point
- perpendicular to direction fo energy transfer
water waves
What are longitudinal waves?
- vibration parallel to direction of energy transfer
- compression and rarefaction
How do you measure the wavelength in a ripple tank?
- use 30cm long ruler
- measure across 10 projected waves
- divide by 10
How do you measure frequency in a wave tank?
- count no. of waves passing point in 10 secs
How do you determine wave speed using a ripple tank?
1) set up ripple tank
2) adjust height of wooden rod,** just touches surface of water**
3) switch on lamp and motor, adjust until low frequency waves can be observed
4) measure wavelength (30cm ruler measure 10 waves, divide by 10)
5) find frequency (no. of waves passing through a point in 10s/ 10)
6)** wave speed = frequency x wavelength**
How do you measure the speed of sound in air?
1) one person bangs two blocks of wood (loud noise)
2) second person starts stopwatch when they see visual sound indication
3) stops watch when noise is heard
How do you measure the speed of a wave in a solid?
1) attach string to vibration generator
2) use 200 g mass and pulley to pull string taut
3) place wooden bridge under string near pulley
4) switch on vibration generator until standing waves can be observed
5) use ruler to measure total length of bridge to vibration generator
6) divide by total number of half-wavelengths, multiply by 2 = wavelength
7) frequency can be seen on vibration generator
