waves

• What type of vibrations occur in transverse waves?

  Vibrations are perpendicular to energy transfer
• What type of vibrations occur in longitudinal waves?

  Vibrations are parallel to energy transfer
• What is the frequency range of ultrasound?

  Above 20,000 Hz
• How is ultrasound used in medical imaging?

  Pulses reflect off tissue boundaries to create images
• What are the three types of seismic waves emitted by an earthquake?

  P, S, and L waves
• What type of wave is a P wave?

  Longitudinal and fast
• What type of wave is an S wave?

  Transverse and slower than P waves
• What do L waves cause during an earthquake?

  Violent shaking of the crust
• How do P and S waves behave as they travel through the Earth?

  They refract due to increasing density
• Why can't S waves travel through the outer core?

  Because they cannot travel through liquids
• What is a black body in terms of radiation?

  A perfect absorber and emitter of radiation
• What type of waves are sound waves?

  Longitudinal
• How does amplitude affect sound?

  It affects the volume of the sound
• How does frequency affect sound?

  It affects the pitch of the sound
• How are echoes used in SONAR?

  To measure distances to submarines and fish
• What happens when light hits a surface?

  It can reflect
• What are the two types of reflection?

  Specular and diffuse
• What is the law of reflection?

  Angle of incidence equals angle of reflection
• What happens to colors when light passes through a filter?

  All colors except the filter color are absorbed
• Why do surfaces appear a certain color?

  Due to the colors of light they reflect
• What are the two types of images?

  Real and virtual
• How does a convex lens affect light?

  It refracts light to a focus
• What can a convex lens do to images?

  Images can be magnified
• What is the formula for magnification?

  Magnification = image height / object height
• What are transparent and translucent materials?

  They transmit light
• What are opaque materials?

  They absorb or reflect light
• What is refraction?

  Light changing speed in different densities
• What happens to light when it travels from less dense to more dense medium?

  It refracts towards the normal
• What happens to light when it travels from more dense to less dense medium?

  It refracts away from the normal
• How does a concave lens affect light?

  It refracts light so it spreads out
• What is the effect of a concave lens on images?

  It diverges light rays
• What happens to the image if an object is more than 2 focal lengths from the lens?

  The image is diminished, inverted, and real
• What is the image like if an object is between 1 and 2 focal lengths from the lens?

  The image is magnified, inverted, and real
• What defines a magnifying glass in terms of object distance?

  The object is less than 1 focal length
• What is true about the image produced by a magnifying glass?

  The image is magnified and bigger than the object
• Why do rays not meet at a point when using a magnifying glass?

  The image produced is virtual
• When does a convex lens produce a virtual image?

  When it is used as a magnifying glass
• What is the distance from the lens to the principal focus called?

  Focal length
• What effect do concave lenses have on light rays?

  They make light rays diverge (spread out)