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. Blackbody radiation is the electromagnetic radiation emitted by a blackbody.

2. The blackbody curve is a characteristic curve which demonstrates that as temperature increases, the wavelength at which maximum intensity occurs decreases.

3. This demonstrates that light doesn’t transfer energy continuously as predicted by classical physics, but rather it emits energy in discrete packets and is quantised, providing evidence for 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 Postulates:

1. Electrons orbit the nucleus in stationary states with fixed angular momentum and energy. Their distance from the nucleus is proportional to their energy.

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

3. The angular momentum of an electron in quantised

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.

The Photoelectric Effect - found that when light is shone onto a metal surface, electrons will be ejected from the surface, demonstrating that light is quantized which provides evidence for 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

Mesons - made up of a quark/anti-quark pair

Contrast the fundamental forces experienced by quarks and leptons

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Describe the Law of Universal Gravitation

The gravitational force of attraction between two masses is proportional to the product of their masses and inversely proportional to the square of the distance between them.

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 and EMF induced in a loop opposes the relative motion across the magnetic field that caused it. This means that kinetic energy is transferred into electrical energy (the current), aligning with the Conservation of Energy.

Explain Faraday’s Law

Faraday’s Law - when a current-carrying conductor experiences a changing magnetic flux, an electromotive force is induced in the circuit proportional to the rate of change of magnetic flux.

Explain relativistic time and length

Relativistic objects experience Time Dilation and Length Contraction.

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T origin L observer

Explain gravitational fields

A gravitational field is the region around a mass in which another mass experiences a gravitational force.

Describe how the detection of muons on Earth’s atmosphere proves special relativity

1. As muons are travelling at relativistic speeds, from the muon’s inertial reference frame, the distance travelled is less than the distance observed at rest due to length contraction.

2. As the distance is contracted, the muons can travel to the Earth’s surface in their lifetime, providing evidence for the theory of special relativity.

Explain the properties of a step-down transformer

np > ns

Vp > Vs

Ip < Is

Explain how transformers work in terms of Faraday’s law and electromagnetic induction.

1. Transformers are made of a primary coil and secondary coil wrapped around an iron core. An alternating current is passed through the primary coil which leads to a changing magnetic flux induced in the core.

2. The magnetic flux then induces an EMF in the second coil, as predicted by Faraday’s law which is: emf = -n(Δθ/Δt).

3. This shows that the induced EMF is proportional to the rate of change of the magnetic flux as well as the number of coils.

Define Magnetic Field

A region in which a force is exerted on magnetic materials.