light and sound

• What type of waves are sound waves?

  Mechanical waves
• Why can't sound waves travel through a vacuum?

  They need a medium to travel through
• How are sound waves classified in terms of oscillation?

  They are longitudinal waves
• What happens to sound waves when they move from air into a solid?

  They cause vibrations of the same frequency
• What is the frequency range of human hearing?

  20 Hz to 20 kHz
• How does frequency relate to pitch in sound waves?

  Higher frequency means higher pitch
• How does amplitude relate to sound volume?

  Greater amplitude means louder sound
• What can seismic waves tell us about the Earth's interior?

  They provide evidence about internal structure
• What does the curvature of seismic wave paths indicate?

  There is a gradual change in density
• What does the absence of seismic waves on the opposite side of the Earth suggest?

  The outer core must be liquid
• What do kinks in P-wave paths suggest?

  There is a sudden change in density
• What do shadow zones indicate about the Earth's core?

  Existence of a solid inner core
• What frequency range do ultrasound waves have?

  Above 20 kHz
• What happens to ultrasound waves at a boundary?

  They are partially reflected
• How can the distance to a boundary be determined using ultrasound?

  By timing the reflection return
• What is echo sounding used for?

  Detecting objects in deep water
• What are the properties of P-waves?

  Longitudinal and travel through liquids and solids
• What are the properties of S-waves?

  Transverse and cannot travel through liquids
• What observation suggests the outer core is liquid?

  S-waves are not detected on the opposite side
• What is the difference between a concave and convex lens?

  Concave curves inwards, convex curves outwards
• What does a convex lens do to parallel rays of light?

  It makes them converge at a point
• What does a concave lens do to parallel rays of light?

  It makes them diverge
• What is the focal length of a lens?

  Distance to the principal focus
• What types of images do concave and convex lenses produce?

  Concave produces virtual, convex can be real or virtual
• What properties can images formed by lenses have?

  Magnified or diminished, upright or inverted
• How is magnification calculated?

  $\text{magnification} =$$\frac{\text{image height}}{\text{object height}}$
• What is the unit of magnification?

  It has no units
• What does each color in the visible light spectrum represent?

  Each has its own wavelength and frequency
• What is specular reflection?

  Reflection from a smooth surface
• What is diffuse reflection?

  Scattering of light from a rough surface
• What do transparent objects do with visible light?

  They transmit visible light
• What do translucent objects do with visible light?

  They transmit and scatter light
• What do opaque objects do with visible light?

  They do not transmit light, absorb and reflect
• How does the color of an object depend on light?

  It depends on wavelengths transmitted and reflected
• How do colored filters work?

  They absorb certain wavelengths and transmit others
• What are the four things that can happen to visible light when it hits an object?

  • Transmitted
  • Absorbed
  • Reflected
  • Refracted
• What are the properties of light waves in the visible spectrum?

  • Each color has a specific wavelength
  • Each color has a specific frequency
• What are the differences between convex and concave lenses?

  • Convex lenses:
  • Curve outwards
  • Converge parallel rays of light
  • Can produce real or virtual images
  • Concave lenses:
  • Curve inwards
  • Diverge parallel rays of light
  • Always produce virtual images
• What are the characteristics of sound waves and their uses?

  • Sound waves:
  • Mechanical and longitudinal
  • Travel through solids, liquids, and gases
  • Uses:
  • Medical imaging with ultrasound
  • Echo sounding for depth measurement
• What are the properties of electromagnetic waves of the same color?

  • Same range of wavelengths
  • Same range of frequencies