CFI Physics Exam 2

Card Set Information

CFI Physics Exam 2
2011-02-23 19:33:40
CFI Physics Exam

CFI Physics Exam 2
Show Answers:

  1. Difference between Transverse and Longitudinal wave?
    • Transverse are perpendicular
    • Longitudinal are parallel
  2. What is the relationship of Intensity of sound source and distance of sound source
    Drops off with square of distance
  3. What is the relationship of period and frequency
    They are reciprocal of each other
  4. Why can you hear sound around a wall?
    Diffraction allows the sound to bend
  5. Explain Resonance Frequency. Ex: 225hz
    • Doubles the frequency before
    • 225
    • 450
  6. What type of waves are sound waves?
    Longitudinal waves
  7. If one tuning fork has a freq of 440Hz and one w/ 444Hz striking at the same time, what do you hear?
    Beats with a freq of 4Hz
  8. What happens to speed of sound as you increase temp?
    Speed of sound increases (speed of sound = 331
  9. How much louder is 40dB than 20dB?
    100 times (dB is log of 10)
  10. If the sound of a siren is coming towards you, what do you hear?
    Higher frequency with shorter wave length
  11. What is the phenomenon of hearing a siren coming toward you?
    Doppler effect
  12. Which coefficient of linear expansion will expand the most: .9, 3, 12, 28
    28 because it is the highest
  13. If you double temp are pressure how does it change?
    It doesn't change
  14. Patient is running a high fever of 40 degrees C, find in Kelvin.
    K= C + 273.15

  15. At 0 K, what is true about gas?
    Volume is zero
  16. Diatomic Gas, such as O2 what kind of kinetic energy can it have?
    Rotational, Vibrational, and Translational
  17. What is the main way earth loses heat?
  18. What is internal energy and what is not?
    Rotational, Kinetic plus Nuclear, Vibrational (movement of the system of a whole is not)
  19. If you had 10kg of brass, and you want to raise all temp from 273K --> 283K c=.384
    • Q=mc/\T
    • Q=(10)(10)(,384)=38.4kJ
  20. When you have a gas that changes back to liquid phase what is happening to internal energy, increasing or giving off?
    Giving off energy (heating up to change solid->liquid->gas)
  21. Floor feels cold and rug feels warmer?
    Tile is a good conductor of heat
  22. What is meant by triple point?
    Solid, liquid, gas properties present, different for each substance
  23. Net charge of closed system does not change
    Conservation of electric charge
  24. 5 things about Electric Field lines
    • 1) Always start at + ends on negative
    • 2) More charge -> more field lines -> strong field
    • 3) NO field inside a charged conductor
    • 4) Field lines are always perpendicular to the surface of a charged object
    • 5) Field lines are always closest together at point and edges
  25. SI of electric unit
  26. Tow charges distance is 1cm, if increase the distance to 4cm, by what factor does the force change?
    Drops by 4 factor or 16
  27. Things about Static Equilibrium
    • 1) The electric field inside a charge is always zero
    • 2) When the conductor reaches equilibrium only the surface can have a net charge
    • 3) The electric field at the surface of the conductor is perpendicular to the surface
    • 4) The surface charge density charge per unit area on a conductor in electric equilibrium is higher at sharp point
  28. If you take cat fur and charge an object, and you hold this object near an uncharged object...
    It will induce separation of charge causing a force of attraction (induction)
  29. Build veindigraph generator where is the safest place for command center?
    In the center
  30. Electric Potential
    Potential energy per unit charged
  31. Device that measure potential difference?
    EGC machine
  32. What is a capacity made up of?
    Two conductors separated by insulator (measured in Farads)
  33. If you are reading a charge in an equopotential...
    No change in potential energy and requires no work
  34. Derived units for Volt
    joules per coulomb
  35. Series and Parallel circuit figure resistance
    • Series
    • R=R1 + R2 + R3....

    • Parallel
    • 1/R= 1/R1 + 1/R2
  36. Of all the unit for electricity, which unit represents a rate?
    Current = I + (C/s)
  37. Characteristics of resistance of wire
    Resistivity, Thickness, length
  38. Which make better insulator and conductor
    • High resistivity = insulator
    • Low resistivity = conductor
  39. Power Derived
    P=I/\V or P=I2V
  40. Magnetic Field lines and Electrical Field lines
    • Magnetic field lines have N and S poles
    • Electrical fields make a complete loop
  41. Shape that takes form around a straight wire
    Concentric circles
  42. Magnetic field strength
  43. Two wires carrying current when will they attract
    Parallel will attract
  44. Cut bar magnet in half what do you get?
    Two north and wound magnets
  45. Suppose you have a silonoid with an incoming wire with loops and an outgoing with loops how do you determine the current?
    Right hand rule
  46. Produce of Magnetic field and area?
    Magnetic Flux (measured in webers)
  47. Lenz's law?
    Current induced, opposed force that produced it
  48. Farad's Law
    Size of EMF is equal to rate of change of magnetic flux
  49. If a transformer has an input of 420V output of 20V
  50. What kind of transform is this? Input of 420 and output of 20V
  51. Why do power companies increase voltage of power cables?
    To fight resistance