Physics Final Boss Flashcards

Explain the Photoelectric Effect

The photoelectric effect experiment demonstrates that when light shines on a metal plate, the energy is transferred to electrons, causing electrons (which are photoelectrons) to be ejected from the plate.

Define Electromagnetic Radiation

Radiant energy consisting of synchronized oscillations of electric and magnetic fields, or electromagnetic waves, propagated at the speed of light in a vacuum.

Explain how Young's double slit experiment provides evidence for the wave model of light

1. The result - Young's double slit experiment demonstrated that when light is shone through two slits, a pattern is produces consisting of bright and dark sports.

2. Interference - When the light passes through the slits, it diffracts which causes the bright and dark spots produced by constructive and destructive interference.

3. Link to waves - Diffraction and interference are both properties of mechanical waves, therefore this experiment provided evidence for the wave model of light.

Describe light as an electromagnetic wave

Light is an electromagnetic wave because it consists of oscillating electric and magnetic fields that travel through space.

Explain the concept of black-body radiation and the significance of the evidence it provides

1. Black-bodies are theoretical objects that absorb all radiation incident upon them and emits electromagnetic radiation based on its temperature.

2. The significance is that it contradicts light being considered as a wave as the black-body curve shows increasing intensity at lower wavelengths. It demonstrates that light emits energy in discrete packets (quantised), proving evidence of the particle nature of light.

Compare the different models of the atom proposed by Rutherford and Bohr

Rutherford’s Atom Model/Classical Physics:

• small, positively charged nucleus

• negative electrons orbiting the nucleus that constantly emit electromagnetic radiation, decreasing energy and only existing for a small period of time

Bohr’s Atom Model:

1. Electrons are in stationary states (not emitting EM radiation)

2. Transitions between energy levels involves the emission/absorption of EM radiation

3. The angular momentum of an electron in quantised

Explain Bohr’s model of the Hydrogen Atom

The Hydrogen Line Spectrum indicated that hydrogen atoms emitted discrete wavelength emissions which suggests that electrons exist in stationary states with discrete energy levels.

Explain the wave-particle duality of light

Young’s Double Slit - Diffraction and interference are both properties of mechanical waves, therefore this experiment provided evidence for the wave model of light.

Black-body Radiation - contradicts light being considered as a wave as the black-body curve shows increasing intensity at lower wavelengths. However, when light was considered as being quantised, the models matched the black-body curve, proving evidence of the particle nature of light.

Identify the six types of quarks

up, down, charm, strange, top, bottom

Identify the six types of leptons

Electron, Electron Neutrino, Muon, Muon Neutrino, Tau, Tau Neutrino

Identify the four gauge bosons

gluon, photon, z boson, w boson

Describe baryons and mesons

Baryons - made up of three quarks or anti-quarks (proton, neutron, sigma). Have a +1 or -1 charge.

Mesons - made up of a quark/anti-quark pair (pion, kaon). Have a charge of 0.

Contrast the fundamental forces experienced by quarks and leptons

Some Will Eat Grapes

QCU

Describe the Law of Universal Gravitation

Every two masses in the universe attract each other with a gravitational force.

State the Three Laws of Planetary Motion

1. Planets move in elliptical orbits, with the Sun at one focus.

2. A line joining a planet to the Sun sweeps out equal areas in equal times (Planets move faster when closer to the Sun).

3. The square of a planet’s orbital period is proportional to the cube of its orbital radius.

State the Two Postulates of Special Relativity

1. The laws of physics are the same in all inertial reference frames.

2. The speed of light in a vacuum has the same value in all inertial reference frames.

State the structure for Paradoxical Scenarios

1. Describe what Person A sees

2. Describe what Person B sees

3. State that the 2 observations are from different inertial reference frames

4. State that the 2 observations are different

5. State that the 2 observations are equally valid therefore paradoxical

6. State that this paradox can be explained by simultaneity, where the observation of one observer can be simultaneous, but the same events observed from a different frame of reference is not seen as simultaneous

Describe Coloumb’s Law

The electrostatic force between two objects is proportional to the product of their charges and inverse to the square of the distance between them.

Explain Lenz’s Law and how it aligns with the Conservation of Energy

Lenz’s Law - the direction of the current induced in a loop opposes the change in the circuit or the magnetic field that produces it.

Conservation of Energy - an induced current will always flow in a direction such that it creates a magnetic field that opposes the change in the inducing field, meaning work is done which is converted into electric energy.

Explain Faraday’s Law and how transformers work

Faraday’s Law - when the magnetic flux linking a circuit changes, an electromotive force is induced in the circuit proportional to the rate of change in flux.

Transformers - if the magnetic field produced by the primary coil changes, the secondary coil will experience a change in magnetic flux. This induces EMF across the secondary coil, resulting in a current according to Faraday’s Law.