CSET 118: Waves

The flashcards below were created by user cornpops on FreezingBlue Flashcards.

  1. Compare the characteristics of sound, light, and seismic waves (e.g.,transverse/longitudinal, travel through various media, relative speed)
    • sound:
    • longitudinal - pulse moving down slinky, air particles move back and forth 
    • travel through gas, liquid and solids but won't carry in a vacuum 
    • travels through air about 340 m/s

    • light:
    • transverse - medium moves at right angles to the direction of the wave
    • travels at 3 x 108 m/s

    • seismic:
    • travel through Earth 
    • can be transverse or longitudinal 
    • longitudinal - P waves, several km per second through crust
    • transverse - S waves, somewhat slower
  2. Explain that energy is transferred by waves without mass transfer and provide examples
    • mechanical waves are variations that travel through a medium carrying energy 
    • as the waves travel through the medium they locally displace some particles in the medium from their normal position
    • those particles then oscillate 
    • example - in a sound wave, air particles oscillate back and forth, creating alternating bands of low and high pressure
  3. Explain how lenses are used in simple optical systems, including the camera, telescope, microscope, and the eye
    • converging lens:
    • outside the focal point - real and inverted
    • inside the focal point - virtual and right-side up 
    • at the focal point - no image

    • diverging lens:
    • the image will be on the same side of the lens, virtual, reduced and upright 

    • the eye:
    • focuses light using the cornea and lens - both converging lenses 
    • lens can change shape or thickness to change the distance of the focal point - adjusts to different diverging rays of light 

    • camera:
    • converging lens creates real image on the sensor or film 

    • telescope:
    • two converging lenses - large one at the opening to collect light, small one in the eyepiece to bring the image to the eye 
    • focal point for both lenses is at the same place

    • microscope:
    • focal length of the objective lens is small
    • eyepiece focal length is long 
    • the object is outside the focal point of the objective lens
    • the image formed by the objective is at the focal point of the eyepiece
  4. Explain and apply the laws of reflection and refraction
    • reflection: the angle of incidence is equal to the angle of reflection 
    • angles are measured with respect to the normal of the reflecting surface

    • refraction: the changing of direction and speed of light when it goes from one medium to another 
    • when entering new medium, angle is deviated toward the normal if the new medium has a higher index of refraction
  5. Compare transmission, reflection, and absorption of light in matter
    • transmission: when light passes through matter 
    • reflection: reflected pulse is upside down, phase change of 180
    • absorption: energy is converted to heat
Card Set:
CSET 118: Waves
2013-07-08 03:25:38

Science CSET
Show Answers: