Physics Overall Flashcards
What are the two groups that fermions are broken down into
quarks and leptons
What are the six flavours of quark?
up down strange charm top bottom
What particles are in the leptons group?
electron muo tau as well as the neutrino counterpart of each
Name the 3 composite particles?
Hadron Baryon Meson
What is a hadron
a term used to describe any particle made of quarks. There are two basic types of hadron and these are Baryon and Mesons
What is a baryon
A subatomic particle made of three quarks. Examples include protons and neutrons
What is a meson
A subatomic particle made of two quarks (usually one quark and one anti quark)
list the two properties of a projectile
all projectiles have a constant acceleartion and a constat horizontal velocity
State the universal law of gravitation
there is a gravitational force between any two objects however it is usually negligible unless at least one of the objects is very large. The force of attractiona cts equally on both objects
Defintion of momentum
momentum is quite simply the product of mass and velocity for an object. It is a vectotr quantity
What is the principle of conversion of momentum
when objects collide(or explode apart) the total momentum of all the objects before the collision is equal to the total momentum of all the objects after the collision in the absence of external forces.
What are the four impluse equations?
ft = mv-mu = area under F-t graph = deltaP
What are the four impluse equations?
ft = mv-mu = area under F-t graph = deltaP
Define cosmic background radiation
it supports the big bang theory and is detected in all directions
If something is in redshift what does that mean in respect to you
it is moving away from you
Define dark energy
explanation for accelerating of the expansion of the universe
Define relativistic length contraction
A phenomenon observed when objects move at high velocity is that their length as measured by a “stationary” observer will appear to contract
Define constructive interference
constructive interference is when waves from two identical sources meet in phase. A detector placed in a position of constructive interference will detect a longer amplitude of wave.
Define destructive interference
destructive interference is when waces from two identical sources meet exactly out of phase(by half a wavelength.) A detector in this position will detect a smaller or even zero amplitude.
Explain why a person walking in front of two speakers will hear changes in the volume of sound when the amplitude of the speakers are constant
As they walk across the room they move through positions where the waves from the two sources meet in and out of phase. When they meet in phase a louder sound is heard due to construcitve interference. when they meet out of phase a quieter sound is heard due to destructive interference.
If Kinetic Energy is lost during a collison is it Elastic or Inelastic
Inelastic
If Kinetic Energy is gained during a collision is it Inelastic or Elastic
Elastic
What unit does Impulse have?
Ns(Newton,Seconds)
Define Dark Matter
makes galaxies spin too fast and you cant protect it easily
What are the four fundamental forces in the standard model?
Electromagnetic - Gravitational - Strong Nuclear Force - Weak Nuclear Force
Each Fundamental Force has a carrying particle - what is the broad name for these particles
boson
What is a Satellite in free fall around
A Planet/Star
What is the speed of light like in a vacuum in terms of all observers.
It is the same
What does the doppler effect cause
shifts in wavelengths of sound and light
What does the hubble-leimatre law allow us to do
Estimate the age of universe
how can we estimate the mass of a galaxy
the orbital speed of stars within it
What is the temperature of stellar objects related to
the distribution of emitted radiation over a wide range of wavelengths
What is redshift? in terms of wavelength
the change in wavelength divided by the emitted wavelength
What emits more radiation per unit surface area:
hotter objects or cooler objects
hotter objects
238
U. what is 92?
92
Atomic Number(the number of protons in the nucleus)
238
U. what is 238?
92
Mass Number (The total number of protons and neutrons in the nucleus)
What units is gravitational Field Strength measured in?
N kg - 1
What units is momentum measured in?
kg m s-1
What is the difference between a vector and a scalar?
Scalars have magnitude only, vectors have magnitude and direction
What is meant by a gravitational field strength of 6.7 N kg-1.
6.7 N of force acts on each kg of mass due to the gravitational field
What is meant by gravitational field strength?
the force applied per unit mass due to a gravitational field.
What is the force mediating particles associated with EM radiation?
photon
What is the standard name given to all particles made from quarks?
Hadrons
When drawing diagrams of electric field lines, will they point towards or away from a negative charge?
Towards
When drawing diagrams of electric field lines, will they point towards or away from a positive charge?
Away
In terms of sub atomic particles, what is an alpha particle?
2 protons and 2 neutrons
A radioisotope has an atomic number of 59. It then emits a beta particle. Its new atomic number will be
60
A radioisotope has an atomic number of 74. It then emits an alpha particle. Its new atomic number will be
72
What is meant by the “threshold frequency” of a metal?
The minimum frequency a photon must have to cause the emission of an electron from a meal surface.
Which photon will have the highest energy, 400nm or 700nm?
400 nm
Describe in simple terms a fusion reaction.
Two smaller nuclei collide to form one large nucleus in a process releasing energy
Describe how E=mc2 is used in the analysis of nuclear reactions.
The mass before the reaction is greater than the mass after, the difference in mass is the quantity which has been converted into energy.
What is meant by the work function of a metal?
The minimum energy a photon must have to cause the emission of an electron from a meal surface.
What is meant by total internal reflection?
When light strikes the inside surface of a material at a large enough angle (larger than critical angle) so that all of the light is internally reflected.
What is meant by critical angle?
The minimal angle of incidence at which total internal relection will take place in a material.
Will the wavelength of light in glass be larger or smaller than the same light in air?
Smaller
A particle travels horizontally underneath a negatively charged plate and above a positively charged plate and deflects upward. What could this particle be?
Any positively charged particle
What units is irradiance measured in?
W m-2
An electron in an atom falls from a high energy level to a lower energy level. What will happen?
A photon will be emitted.