Physics FAQ Hub
Worked answers grouped by topic. 553 indexable entries across ten clusters.
This hub indexes 553 worked physics questions on Physics Mastery Hub, grouped into ten topical clusters so you can browse by area. Each entry on a child page contains a one-line answer followed by a short explanation and links to the relevant formula or article in the library.
For step-by-step calculations rather than conceptual Q&A, see the calculator library. For concise definitions, see the glossary and the "what is X" answer pages.
Mechanics & dynamics (109)
- A 10 n force acts over 5 m in the direction of mot…
- A 2 kg object accelerates at 3 m/s² what is the net…
- A 3 kg object moving at 4 m/s has momentum of…
- A 4 kg object experiences a net force of 12 n its…
- A 5 kg block slides 10 m on a surface with muk 03 w…
- A ball is thrown horizontally from a cliff which g…
- A ball is thrown upward at its highest point its v…
- A beam of light crossing an accelerating elevator…
- A magnetic field exerts force on…
- A projectiles horizontal velocity ignoring air res…
- A quantum harmonic oscillator has energy levels…
- A refrigerator works by…
- A rigid bodys rotational kinetic energy is…
- A spring with k 200 nm is compressed 005 m elastic…
- According to relativity a massive object can reach…
- An athlete exerts a force over 02 s to accelerate…
- Angular momentum…
- Buoyancy force on a submerged object equals…
- Centre of mass of a uniform rod is located at…
- Centripetal acceleration for circular motion is…
- Centripetal force…
- Conservation of mechanical energy…
- Coriolis acceleration for a particle moving with v…
- Energy levels in a hydrogen atom are quantised acc…
- Energy stored in a capacitor…
- Escape velocity from earth radius r mass m is give…
- For a rigid body rolling without slipping on a sur…
- For an elastic collision between a heavy ball mass…
- For simple harmonic motion acceleration is proport…
- Gravitational potential energy…
- Hubbles law states that the recessional velocity o…
- If speed doubles while mass stays fixed kinetic en…
- In a completely inelastic collision between equal…
- In an ideal gas internal energy u depends only on…
- Kinetic energy…
- Light passing near a massive object is bent becaus…
- Lorentz force…
- Magnetic force on a moving charge…
- Mass energy equivalence…
- Momentum…
+ 69 more in this group.
Rotational & orbital motion (13)
- A car rounds a flat curve of radius 50 m at 20 m/s…
- A gyroscope precesses because…
- A satellite in a lower orbit compared to one in a…
- An object in uniform circular motion has constant…
- Atomic orbitals with l 2 are called…
- If no net torque acts on a rotating body what is c…
- Keplers third law states that orbital period t and…
- The impedance of a series rlc circuit at angular f…
- The schwarzschild radius of a nonrotating black ho…
- Torque…
- What is the cause of galactic rotation curves bein…
- Which statement about gps satellite clocks is corr…
- Why do gps satellites need relativity corrections…
Electromagnetism & circuits (48)
- A charge q at rest in an electric field e experien…
- A parallelplate capacitor with plate separation d…
- An electric field exists around…
- An emf of 10 v drives a current of 2 a through a r…
- Capacitance is the ability of a component to…
- Capacitance…
- Coulomb constant…
- Coulombs law…
- Electric field lines point…
- Electric field of a point charge…
- Electric power…
- Electromagnetic waves are transverse because…
- Faradays law of induction…
- Faradays law states that an emf is induced when…
- Gausss law for electricity states that the electri…
- In an rl circuit time constant tau lr means…
- In resonance of an lc circuit what is the resonant…
- In series circuits the current through each compon…
- Lenzs law states that induced current…
- Like charges…
- Magnetic field around a wire…
- Magnetic flux phi through an area a with field b at…
- Magnetic flux…
- Magnetic susceptibility artefacts in mri occur nea…
- Maxwell added the displacement current term becaus…
- Ohms law states v ir what does r represent…
- Ohms law…
- Selfinductance opposes changes in current because…
- Specific heat capacity describes…
- The aharonov bohm effect demonstrates…
- The biot savart law gives the magnetic field produ…
- The cyclotron frequency of a charge q in field b i…
- The jeans maxwell stress tensor describes…
- The maxwell boltzmann distribution describes…
- The phase difference between voltage and current i…
- The photoelectric effect shows that light behaves…
- The probability current in quantum mechanics descr…
- The si unit of magnetic field strength b is…
- The wave equation for electromagnetic waves in vac…
- What is the direction of conventional current…
+ 8 more in this group.
Waves, optics & sound (64)
- A concave mirror converges…
- A laser differs from ordinary light because it is…
- Chromatic aberration in lenses occurs because…
- Coherence length of a light source is defined as…
- Compton scattering demonstrated that photons have…
- De broglie wavelength…
- Diffraction grating…
- For light travelling in vacuum the spacetime inter…
- Gravitational lensing is caused by…
- Gravitational waves are produced primarily by…
- In a diffraction grating constructive interference…
- In the weakfield limit gravitational waves are…
- In waveguides the cutoff frequency depends on…
- Larmor (cyclotron) frequency…
- Lens formula…
- Light climbing out of a gravitational field is obs…
- Ligo detected gravitational waves from…
- Medical ultrasound typically uses frequencies in…
- Nonlinear optics describes phenomena when…
- Polarisation shows that light is…
- Reflection follows…
- Snells law of refraction states…
- Snells law of refraction…
- Solitons in optical fibres maintain their shape be…
- Sound travels fastest in…
- Sound waves are…
- Speckle patterns in laser light arise from…
- Stimulated emission used in lasers is described by…
- The airy disc in diffractionlimited optics has ang…
- The amplitude of a wave is…
- The characteristic frequency of gravitational wave…
- The concept of optical coherence tomography oct is…
- The cosmic microwave background radiation is evide…
- The doppler effect for sound explains why a siren…
- The doppler formula for a source moving toward a s…
- The frequency of a guitar string increases if…
- The intensity of a wave is proportional to…
- The kramers kronig relations applied to optics con…
- The optical path difference for two coherent sourc…
- The photonic bandgap in a photonic crystal prevent…
+ 24 more in this group.
Thermodynamics & statistical physics (33)
- A phonon is the quantum of…
- An adiabatic process involves…
- An ideal gas undergoes isothermal expansion from v…
- Carnot efficiency…
- Conduction of heat requires…
- Entropy is a measure of…
- First law of thermodynamics…
- For a reversible process total entropy change of u…
- Fouriers law of heat conduction is…
- Heat flows naturally from…
- Ideal gas law…
- Stefan boltzmann law…
- The adiabatic index gamma cpcv for a monatomic ideal g…
- The adiabatic theorem in quantum mechanics states…
- The carnot efficiency of a heat engine operating b…
- The coefficient of performance cop of a carnot ref…
- The efficiency of a heat engine is maximised by…
- The first law of thermodynamics is a statement of…
- The ideal gas law is pv nrt what does n represent…
- The kelvin temperature scale starts at…
- The second law of thermodynamics states…
- The specific absorption rate sar in mri represents…
- The specific heat of a debye solid at very low tem…
- The stefan boltzmann law relates radiated power to…
- The third law of thermodynamics nernst theorem sta…
- The zeroth law of thermodynamics states…
- Van der waals equation modifies the ideal gas law…
- What is latent heat…
- Which formula gives the luminosity temperature rel…
- Which gas behaves most like an ideal gas…
- Which thermodynamic cycle drives most petrol engin…
- Which thermodynamic process occurs at constant tem…
- Which type of nuclear reaction powers thermonuclea…
Quantum & atomic physics (29)
- Bohrs model of the hydrogen atom quantises…
- Heisenberg uncertainty principle…
- In quantum mechanics operators corresponding to ob…
- Pair annihilation of an electron and positron prod…
- Perturbation theory in quantum mechanics is valid…
- Plancks constant h is approximately…
- Plancks relation…
- Quantum chromodynamics qcd describes…
- Quantum decoherence explains…
- Quantum error correction uses…
- Quantum field vacuum is not truly empty because of…
- Quantum tunnelling explains…
- Spontaneous symmetry breaking in quantum field the…
- The classical electron radius re arises when…
- The fractional quantum hall effect arises from…
- The heisenberg uncertainty principle limits simult…
- The qed prediction of the electrons anomalous magn…
- The spin quantum number of an electron can be…
- The spin statistics theorem states that…
- The wigner function in quantum mechanics is…
- Time dependent schrodinger equation…
- What did the doubleslit experiment with electrons…
- What is quantum entanglement…
- What is the nucleus of a hydrogen atom composed of…
- Which experiment proved the quantisation of atomic…
- Which interpretation of quantum mechanics holds th…
- Which postulate of quantum mechanics states the st…
- Which quantum number describes the shape of an ato…
- Which symbol represents the reduced planck constan…
Nuclear, particle & high-energy physics (32)
- A neutrino is…
- A proton is composed of…
- Alpha decay emits…
- Baryon acoustic oscillations baos are used as…
- Beta decay beta emits…
- Betaplus beta decay emits…
- Diffusion mri measures…
- Fission involves…
- Fusion involves…
- Half life decay…
- In the electroweak theory the w and z bosons get t…
- In the standard model quarks are held together by…
- Magnetars are neutron stars with…
- Neutron stars are supported against collapse by…
- Nuclear isomers are nuclei with…
- Nuclear medicine spect uses…
- Primordial nucleosynthesis bbn predicts a helium m…
- Proton decay if it exists is predicted by…
- Proton therapy has clinical advantage over convent…
- The ckm matrix describes…
- The gamow factor in nuclear fusion determines…
- The pmns matrix describes…
- The proton proton chain in the sun primarily produ…
- The qvalue of a nuclear reaction is…
- The shell model of the nucleus was developed by…
- The term magic numbers in nuclear physics refers t…
- What is nucleosynthesis…
- What is the role of a moderator in a nuclear fissi…
- What is the rprocess in stellar nucleosynthesis…
- Which conservation law is obeyed in all nuclear re…
- Which decay mode involves a nucleus emitting two e…
- Which of the following is a boson…
Relativity, gravity & cosmology (34)
- A black holes event horizon is the boundary where…
- A geodesic in general relativity is…
- A minkowski diagram is used to…
- A positive cosmological constant is associated wit…
- A quasar is…
- At v 08c the lorentz factor gamma is approximately…
- Clocks deeper in a gravitational field compared wi…
- Dark matter was first inferred from…
- Einsteins field equations connect spacetime curvat…
- Frame dragging refers to…
- Free fall in general relativity is best described…
- General relativity describes gravity as…
- Hawking radiation predicts that black holes…
- In flat spacetime which curvature object vanishes…
- In special relativity simultaneity is…
- Length contraction affects an objects dimension…
- Multipole expansion of radiation shows that electr…
- Relativistic effects become most noticeable when a…
- Special relativity predicts that a moving clock co…
- The birkhoff theorem in general relativity states…
- The cosmic inflation epoch occurred…
- The flatness problem in cosmology refers to…
- The horizon problem in cosmology refers to…
- The lambdacdm model of cosmology includes…
- The schwarzschild event horizon at r 2gmc2 is…
- The schwarzschild radius of a black hole is…
- The spacetime interval is encoded by the…
- The spectral index ns approx 096 measured from cmb anis…
- The twin paradox is resolved because one twin…
- The virial theorem for a bound gravitational syste…
- What is the big bang…
- What is the lorentz factor gamma…
- Which lorentz transformation for the xcoordinate i…
- Which statement about gravitational redshift near…
Astrophysics & stellar physics (16)
- Cepheid variable stars are used to measure distanc…
- Gamma rays are…
- Pulsar timing arrays ptas are sensitive to gravita…
- The age of stars can be estimated from…
- The chandrasekhar friedman schutz instability conc…
- The frank starling mechanism relates cardiac outpu…
- The h r diagram plots stars by…
- Type ia supernovae are used as standard candles be…
- What are pulsars…
- What determines the colour of a star…
- What is a supernova…
- What is the chandrasekhar limit…
- What is the closest star to earth after the sun…
- What is the galactic centre of the milky way likel…
- What is the name of our galaxy…
- What type of star will the sun eventually become…
Fluids & continuum mechanics (7)
Other physics questions (168)
- A driven oscillator at resonance is characterised…
- A transformer changes…
- Acoustic impedance z of a medium is defined as…
- Amperes law…
- An induction motor operates on the principle of…
- Anderson localisation occurs when…
- Archimedes principle…
- Asymptotic freedom in qcd means…
- At the triple point a substance…
- Baryogenesis explains why the universe contains ma…
- Beats are produced when…
- Berrys phase is…
- Bose einstein and fermi dirac statistics differ fr…
- Bose einstein condensation occurs when…
- Boyles law states that for a fixed amount of gas a…
- Bremsstrahlung radiation in an xray tube is produc…
- Colour confinement in qcd explains why…
- Continuity equation…
- Cooper pairs in superconductors are…
- Cosmic ray primary particles are mostly…
- Cp violation in particle physics was first observe…
- Deep inelastic scattering experiments at slachera…
- Density matrix formalism is used to describe…
- Einsteins equation e mc2 states that…
- Electrocardiography ecg measures…
- Enthalpy h is defined as…
- For a blackbody spectral radiance is given by…
- For timelikeseparated events which path maximises…
- Fractal geometry in physiology is most prominently…
- Gauge invariance in electromagnetism means…