Waves properties Flashcards
Oscillations
The repeated and regular fluctuations above and below the same position
Longitudinal waves
the vibrations are parallel to the direction of wave travel.
Transverse waves
the vibrations are perpendicular to the direction of the wave travel
Mechanical wave
cause oscillations of particles in a solid, liquid or gas and must have a medium to travel through
medium
a material which a wave can be transmitted through
Electromagnetic waves
cause oscillations in electrical and magnetic fields
Rest position
the undisturbed position of particles or fields when they are not vibrating
displacement
the distance that a certain point in the medium has moved from its rest position
peak
the highest point above the rest position
trough
the lowest point below the rest position
amplitude
the maximum displacement of a point of a wave from it’s rest position
wavelength
distance covered by a full cycle of the wave, usually measured from peak to peak or trough to trough
time peroid
the time taken for a full cycle of the wave usually measured from peak to peak or trough to trough
frequency
the number of waves passing a point each second
how does sound reach our ear
when sound is created the air particles vibrate and collide with each other, causing the vibrations to pass between air particles. The vibrating particles pass the sound through to a person’s ear and vibrate the ear drum.
Measuring waves in a ripple tank blurt dis practical rn u *****
- Set up the ripple tank as shown in the diagram with about 5 cm depth of water.
- Adjust the height of the wooden rod so that it just touches the surface of the water.
- Switch on the lamp and motor and adjust until low frequency waves can be clearly observed.
4.Measure the length of a number of waves then divide by the number of waves to record wavelength. It may be more practical to take a photograph of the card with the ruler and take measurements from the still picture.
- Count the number of waves passing a point in ten seconds then divide by ten to record frequency.
6.Calculate the speed of the waves using: wave speed = frequency × wavelength.
hazard consequence and control measures of measuring waves practical in a ripple tank
hazard: Electrical components near water
Shock and damadge to components
Secure electrical components before adding water taking care not to splash
Required practical - measuring waves in a solid
- Attach a string or cord to a vibration generator and use a 200 gram (g) hanging mass and pulley to pull the string taut as shown in the diagram. Place a wooden bridge under the string near the pulley.
- Switch on the vibration generator and adjust the wooden bridge until stationary waves can be clearly observed.
- Measure the length of as many half wavelengths (loops) as possible, divide by the number of half wavelengths (loops). This is half the wavelength, doubling this gives the wavelength.
- The frequency is the
frequency of the power supply. - Calculate the speed of the waves using: wave speed = frequency × wavelength.
Hazard consequence and control measures of Required practical - measuring waves in a solid
Cord snapping
damage to eyes
eye protection goggles
