Physics Unit 2 Flashcards
Fill in the blanks:
Electrical charges ______ and opposite charges _____
Repel and Attract
What do field lines show
The direction of the force experienced by a positive charge
If field lines are closer together what does that mean?
The field is stronger
Name the most famous particle accelerator
LHC
What are particle accelerators used for
Accelerators use electric fields to contain and accelerate charged particles to very high speed.
In terms of magnetic forces, what hand is positive?
Right
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)
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.
What are the four fundamental forces?
Electromagnetic - Gravitational - Strong Nuclear Force - Weak Nuclear Force
Each Fundamental Force has a carrying particle - what is the broad name for these particles
boson
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)
Define Nuclear Fission
A single large nucleus is split producing two smaller nuclei and neutrons in a process that releases energy
Define Nuclear Fusion
Two small nuclei are fused together to produce a larger nucles.
When does refraction of light happen?
When light moves from one medium to another.
What is the refractive index of air and vacuum
1.0
When will total internal reflection occur?
When the angle of incidence inside the material is attempting to leave and it is greater than the critical angle
Define interference
A property exhibited by waves and is considered a test for whether something is actually a wave at all
What are diffraction grating used for?
To cause intereference in patterns in light
What is a photon?
A small bundle of energy
What do you call the minimum energy requirement to eject an electron
The work function.
What do you call the minimum frequency requirement to eject an electron
Threshold Frequency
What happens if the incident photon contains more energy than the work function?
The excess energy is given to the ejected electron in the form of kinetic energy
In terms of the photoelectric effect, does the plate need to be negatively or positively charged?
Negatively charged
Define Irradiance
power per unit area
Magnetic fields are used to contain the plasma inside the fusion reactor.
Explain why it is necessary to use a magnetic field to contain the plasma.
Plasma would cool down if it came
too close to the sides (and reaction
would stop)
Methods to improve an irradiance experiment
Black cloth to reduce reflections
Explain how dark lines in the spectrum of sunlight are produced.
photons of particular frequencies are absorbed in the suns upper atmosphere
State two features of the Bohr model of the atom.
A (central) positively charged nucleus. Each line in a spectrum is produced when an electron moves from one energy orbit to another.
State two features of the Bohr model of the atom.
A (central) positively charged nucleus. Each line in a spectrum is produced when an electron moves from one energy orbit to another.
