Edexcel GCSE Combined Science: Wave Properties

Edexcel GCSE Combined Science: Wave Properties - Physics Paper 2

1. Understanding Waves

Waves are disturbances that transfer energy without transferring matter. Imagine dropping a pebble into a pond - the ripples spread outwards, but the water itself doesn't travel far. That's a wave!

2. Types of Waves

There are two main types of waves:

a) Transverse Waves: * The oscillations (vibrations) are perpendicular to the direction the wave travels. * Examples: Light waves, water waves, and waves on a string.

b) Longitudinal Waves: * The oscillations are parallel to the direction the wave travels. * Imagine a slinky - push and pull it, and you'll see compressions and rarefactions (stretched parts) move along. * Examples: Sound waves, ultrasound waves, and seismic waves.

3. Wave Characteristics

Waves have several important characteristics:

a) Amplitude: The maximum displacement of a point on a wave from its rest position. It determines the wave's intensity (loudness for sound, brightness for light).

b) Wavelength: The distance between two corresponding points on a wave, e.g., two crests or two troughs.

c) Frequency: The number of complete waves passing a point in one second. Measured in Hertz (Hz).

d) Speed: The distance a wave travels in one second. It depends on the medium through which the wave travels.

Important Relationship: Wave speed = Frequency x Wavelength

4. Wave Behaviors

Waves exhibit interesting behaviors:

a) Reflection: When a wave hits a boundary, it bounces back. Think of a ball bouncing off a wall.

b) Refraction: When a wave passes from one medium to another, it changes direction and speed. This happens because the wave speed changes. Think of a straw in a glass of water, appearing bent.

c) Diffraction: Waves spread out as they pass through an opening or around an obstacle. This explains why you can hear someone talking around a corner.

d) Interference: When two waves meet, their amplitudes combine. * Constructive Interference: The amplitudes add up, making a larger wave. * Destructive Interference: The amplitudes cancel each other out, making a smaller wave.

5. Exam Tips

• Know the definitions of key terms.
• Understand the difference between transverse and longitudinal waves.
• Be able to calculate wave speed, frequency, and wavelength.
• Practice drawing diagrams of wave behavior.
• Familiarize yourself with the practical applications of waves (e.g., ultrasound in medical imaging, sound waves in music).

Good luck with your exams!