Properties of waves

• Waves are one of the ways in which energy may be transferred between stores.
• Waves can be described as oscillations or vibrations.
• Longitudinal waves are waves that move in the same direction as the direction in which the particles are vibrating, with the vibrations parallel to the direction of wave travel.
• Transverse waves are waves that move in a direction at right angles to the way in which the particles are vibrating, with the vibrations at right angles to the direction of wave travel.
• Mechanical waves cause oscillations of particles in a solid, liquid or gas and must have a medium to travel through.
• Electromagnetic waves cause oscillations in electrical and magnetic fields.
• All waves transfer energy but they do not transfer matter.
• Parts of a wave are described using the terms: rest position, displacement, peak, trough, amplitude, wavelength, time period, and frequency.
• A wave is described using a diagram.
• Wave period and wave speed are related terms.
• Measuring the speed of sound in air is a required practical.
• Measuring waves in a ripple tank is a required practical.
• Measuring waves in a solid is a required practical.
• Waves are one way in which energy may be transferred between stores.
• Waves are one way in which energy may be transferred between stores.
• Both mechanical and electromagnetic waves will transfer energy but not matter.
• The time period of a wave can be calculated using the equation: Time period = 1 ÷ frequency.
• The speed of a wave can be calculated using the equation: wave speed = frequency × wavelength
• Waves are one way in which energy may be transferred between stores.
• Both mechanical and electromagnetic waves will transfer energy but not matter.
• Wave period and wave speed are important concepts in understanding waves.
• The speed of sound in air can be calculated using the equation: v = √(d/t), where v is measured in metres per second (m/s), d is measured in metres (m), and t is measured in seconds (s).
• The accepted value for the speed of sound in air is 330 m/s.
• Both mechanical and electromagnetic waves will transfer energy but not matter.
• Waves are one way in which energy may be transferred between stores.
• A ripple tank can be used to measure and calculate frequency, wavelength and the speed of waves on the surface of the water.
• A ripple tank is a transparent shallow tray of water with a light shining down through it onto a white card below in order to clearly see the motion of the ripples created on the water’s surface.
• Ripples can be made by hand but to generate regular ripples it is better to use a motor for the ripple tank
• The method involves setting up the ripple tank as shown in the diagram with about 5 cm depth of water.
• The aim of the ripple tank experiment is to measure the frequency, wavelength and speed of waves in a ripple tank.
• The height of the wooden rod should be adjusted so that it just touches the surface of the water in the ripple tank experiment
• The lamp and motor in the ripple tank experiment should be adjusted until low frequency waves can be clearly observed.
• The length of a number of waves should be measured and divided by the number of waves to record wavelength in the ripple tank experiment
• It may be more practical to take a photograph of the card with the ruler and take measurements from the still picture.
• Waves are one way in which energy may be transferred between stores.
• The number of waves passing a point in ten seconds should be counted in the ripple tank experiment and divided by ten to record frequency.
• Both mechanical and electromagnetic waves will transfer energy but not matter.
• The speed of the waves can be calculated using: wave speed = frequency × wavelength.
• Wave period and wave speed are important factors in understanding waves.
• Measuring the speed of sound in air is a common method for understanding waves.