waves Flashcards
what are waves produced by
oscillating or a vibrating system
what are oscillation and vibration
repetitive motions about an equilibrium in a closed path
what are progressive waves
is a wave that travels with time along the direction of propagation of the wave
what are stationary waves
a wave where the profile of the wave does not propagate with time
how can stationary waves be produced
through musical instruments such as guitars
list 3 points for mechanical waves
requires medium to transfer energy from one point to another
made up of vibrating particles of a medium
water waves, sound waves, and seismic waves on the surface of the earth are mechanical waves
list 3 points for electromagnetic waves
does not require a medium
made up if oscillating electric and magnetic fields perpendicular to one another
radio waves, light waves and gamma rays are examples of them
compare transverse waves and longitudinal waves
particles of the medium vibrate in the direction perpendicular to the direction of the propagation of the wave
particles of the medium vibrate in the direction parallel to the direction of propagation of the wave
made up of crests and troughs
made up of consecutive compressions and rarefactions
what is the definition of amplitude, A
maximum displacement of a particle from its equilibrium position
what is the definition of period, T
the time taken by a particle to make one complete oscillation or by a source to produce one complete cycle of wave
what is the definition of frequency, f
number of complete oscillations made by a particle or number of cycles of waves produced by a source in one second
what is the definition of wavelength, lambda
distance between two consecutive points in phase
what is the definition of wave speed, v
distance travelled per second by a wave profile
what is the formula for speed of wave
v = f lambda
sketch the graph of displacement against time and distance for waves
d
what are the two dippers used in ripple tank
plane dipper and spherical dipper
how does oscillating systems experience energy loss
external damping
loses energy to overcome friction to sir resistance
internal damping
loses energy because stretching and compression if the vibrating particles in the system
what is damping
damping is the reduction in amplitude in an oscillating system due to loss of energy.
during damping, the oscillating frequency remains constant while the oscillating amplitude decreases.
how can the effect of damping be overcome
applying periodic external force on the oscillating system. the periodic external force transfers energy into the oscillating system to replace the energy lost.
the system is said to be in forced oscillation
how does an oscillating system be at resonance
when a periodic force is applied to an oscillating system at its natural frequency
what happens during resonance
the system oscillates with its natural frequency
system oscillates with maximum amplitude
what is wavefront
a surface over in which the wave is constant
what happens to angle of incidence and angle of reflection when wave is reflected
angle of incidence = angle reflection
what happens to the wavelength after reflection of wave
no change
what happens to the frequency when wave is reflected
no change
what happens to the direction of propagation when wave is reflected
changes with the condition that the angle of incidence is the same as angle of reflection
try to draw the diagram for reflection of water waves
kn
give 4 applications of reflection of waves in daily life
ultrasonic waves
used in medical field to examine a foetus or other internal organs
radio waves
from communication satellites are reflected by the parabolic dish and focussed into the antenna in the feed horn
technology of ultrasonic of reflection
which is known as sonar helps to detect areas which have a lot of fish. transducer transmit waves into the water and these waves are reflected by the fish to the transducer
patterns of reflected sound waves caused by different rocks
enable the location, depth and structure of the sea bed which contain sources if natural gas to be identified
solve problem involving reflected waves
sa
what does refraction of waves mean
the change in direction if propagation of waves caused by the change in the velocity of waves when the waves propagate from one medium to another
what influence speed of water waves
depth of water
what influence speed of sound waves
density of air
what influence speed of light wave
optical density if medium