CFI Physics Exam 2
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CFI Physics Exam 2
CFI Physics Exam
CFI Physics Exam 2
Difference between Transverse and Longitudinal wave?
Transverse are perpendicular
Longitudinal are parallel
What is the relationship of Intensity of sound source and distance of sound source
Drops off with square of distance
What is the relationship of period and frequency
They are reciprocal of each other
Why can you hear sound around a wall?
Diffraction allows the sound to bend
Explain Resonance Frequency. Ex: 225hz
Doubles the frequency before
What type of waves are sound waves?
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
What happens to speed of sound as you increase temp?
Speed of sound increases (speed of sound = 331
How much louder is 40dB than 20dB?
100 times (dB is log of 10)
If the sound of a siren is coming towards you, what do you hear?
Higher frequency with shorter wave length
What is the phenomenon of hearing a siren coming toward you?
Which coefficient of linear expansion will expand the most: .9, 3, 12, 28
28 because it is the highest
If you double temp are pressure how does it change?
It doesn't change
Patient is running a high fever of 40 degrees C, find in Kelvin.
K= C + 273.15
At 0 K, what is true about gas?
Volume is zero
Diatomic Gas, such as O
what kind of kinetic energy can it have?
Rotational, Vibrational, and Translational
What is the main way earth loses heat?
What is internal energy and what is not?
Rotational, Kinetic plus Nuclear, Vibrational (movement of the system of a whole is not)
If you had 10kg of brass, and you want to raise all temp from 273K --> 283K c=.384
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)
Floor feels cold and rug feels warmer?
Tile is a good conductor of heat
What is meant by triple point?
Solid, liquid, gas properties present, different for each substance
Net charge of closed system does not change
Conservation of electric charge
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
SI of electric unit
Tow charges distance is 1cm, if increase the distance to 4cm, by what factor does the force change?
Drops by 4 factor or 16
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
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)
Build veindigraph generator where is the safest place for command center?
In the center
Potential energy per unit charged
Device that measure potential difference?
What is a capacity made up of?
Two conductors separated by insulator (measured in Farads)
If you are reading a charge in an equopotential...
No change in potential energy and requires no work
Derived units for Volt
joules per coulomb
Series and Parallel circuit figure resistance
Of all the unit for electricity, which unit represents a rate?
Current = I + (C/s)
Characteristics of resistance of wire
Resistivity, Thickness, length
Which make better insulator and conductor
High resistivity = insulator
Low resistivity = conductor
P=I/\V or P=I
Magnetic Field lines and Electrical Field lines
Magnetic field lines have N and S poles
Electrical fields make a complete loop
Shape that takes form around a straight wire
Magnetic field strength
Two wires carrying current when will they attract
Parallel will attract
Cut bar magnet in half what do you get?
Two north and wound magnets
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
Produce of Magnetic field and area?
Magnetic Flux (measured in webers)
Current induced, opposed force that produced it
Size of EMF is equal to rate of change of magnetic flux
If a transformer has an input of 420V output of 20V
What kind of transform is this? Input of 420 and output of 20V
Why do power companies increase voltage of power cables?
To fight resistance