waves Flashcards
what is a longitudinal wave?
a wave where the particle oscillations are parallel to the energy transfer
what is a transverse wave?
a wave where the particle oscillation are perpendicular to the energy transfer
how do you work out the wavelength of a wave in a ripple tank?
- shine a light above the ripple tank so the waves reflect onto paper below
- turn the ripple tank so the waves have a low frequency
- measure with a ruler the length across ten of the lines
- divide this by 10 to work out the length of just one wave
what is amplitude?
the maximum displacement of a point in a wave from its original position
what is wavelength?
the distance from one point on a wave to the same point on an adjacent wave
what is frequency?
the number of waves passing a point each second ( 1Hz is one wave a second )
wave speed =
wavelength x frequency
frequency =
1 / time
what is ultrasound and why is it useful?
sound with a higher frequency than that a human can hear
it is useful in medicine and industry
how is ultrasound used to locate things e.g a baby?
these waves partially reflect when they meet a boundary of different media
the time taken for the wave to reflect back to the meter can be used to calculate the distance to the boundary
what type of waves are p-waves and how fast do they travel?
longitudinal, travel at the speed of sound, change speeds in liquids and solids
what type of waves are s-waves and what can’t they do?
transverse, cannot travel through liquids
what measurement of wavespeed always in?
m/s
how can you measure the speed of sound in air?
person a makes a sound
person b, standing far away, starts a stopwatch when they see the action and stops it when they hear the sound
how do we know the wave moves not the water?
place a cork in the water and it will bob and not be carried with the wave through the water
