Physics AAMC Qpack Flashcards
The chemical behavior of an element depends on?
The chemical behavior of an element depends on interactions and bond formation
An element can be identified solely by the…
Number of protons, also known as the atomic number
1 Volt is equal to how many J/C?
1 Volt = 1 J/C
Formula used to calculate the frequency of a light when given the wavelength
Frequency is equal to the speed of light divided by the wavelength
What is the phase difference corresponding to destructive interference?
The phase difference corresponding to a half of a wave is 180 degrees - a half of a wave difference in phase between two waves is destructive interference
How does wavelength relate to period?
There is a direct relationship between -> the wave with the shortest wavelength has the shortest period
What is the relationship between frequency and period?
Frequency and period are inversely related - the higher the frequency the lower the period
Frequency = 1 / period
Period:
Definition
The time it takes to complete a cycle
Formula for determining period from frequency:
Period = 1/frequency
Comparison of the frequencies of the fourth and third harmonics:
Harmonics are related to frequency by a whole number, you multiply or divide the frequency by the number of the harmonic to get its frequency
What is the Dopler equation?
Change in wavelenght over original wavelength equals velocity (of the movement) over the speed of the electromagnetic wave (c)
The relationship between speed change and change in wavelegth according to the Doppler effect?
An increase in speed causes an increase in detected wavelength
What is the essence of the Doppler effect?
The increase in distance between radio wave peaks due to the jet speed causes the received wavelength to be lengthened - as the speed of an object moving away from the receiver increases the distance between adjacent peaks of transmitted waves also increases
What is the Doppler Equation?
(In terms of frequency)
The frequency change depends inversely on the speed of the wave in the medium (c)
Why are the changes from the Doppler effect greater on sound waves than electromagnetic waves?
The velocity of sound is smaller than the velocity of an electromagnetic wave (the c of sound is less than the c of electromagnetic waves) - so for the same relative velocity (v) the frequency and wavelength shifts are much greater for sound
If the receiver and an object emitting a sound are moving at the same velocity what is the frequency change detected by the receiver?
There is no relative motion between the sound emitter and sound receiver so there is no frequency shift
An approaching Doppler shift of light is called a..
When the wavelenght of an object decreases it is referred to as a blue shift, often associated with an object getting closer
A Doppler shift when light is moving away is called…
A red shift - the wavelength is increasing and the frequency is decreasing
When an object is floating what does that tell you about the relationship between the buoyant force and the weight?
When an object is floating it implies that the weight is balanced by the buoyant force
Refraction
The bending of the path of light waves as it passes across the boundary of two media
What causes refraction?
Refraction is caused by the change in speed experienced by a wave when it changes medium
What is the normal line when talking about refraction?
The normal line is a line drawn perpendicular to the boundary at a point of incidence
When is light refracted towards the normal line?
When a ray of light passes a boundary moving to a material where it travels slower, results in the light ray bending towards the normal line
What happens when a light ray crosses a boundary into a material in which it travels faster?
If light passes across a boundary into a medium in which it travels faster the light ray will bend away from the normal line
What is the equation of Snell’s Law?
refractive index of the medium x the angle of incidence = refractive index of medium x angle of refraction
Why does melting occur at a constant temperature?
Melting occurs at a constant temperature because a certain amount of energy (Latent heat of fusion) is needed to convert a substance from its solid to its liquid state - the temperature of a solid will not increase until all of the solid has become liquid
Equation to calculate the electric field when given voltage, current, resistance, and length
electric field = (Volts - [current x resistance]) / Length
What effect will increasing the number of incident photons have on the electrons?
Change the number of incident photons affects only the number of electrons not their energies
What effects the energy of electrons in a vacuum photodiode dector
The electron energies depend on the energy of the photon, the cathode work function, and the potential difference between the cathode and anode
How is velocity of a particle effected in an electric field?
A charged particle accelerated in an electric field - the electron starts with a velocity that increases as it approaches the anode through the vacuum
