A Level Physics Constants, Data Sheets and Exam Board Specific Formulae Sheets
This page provides a complete list of A Level Physics constants, equations, and relationships you need for exams. These values are essential for calculations across mechanics, electricity, waves, and quantum physics.
Click to scroll to;
List of Useful Physical Constants
| Symbol | Quantity | Value | Units |
| c | speed of light in a vacuum | 3×108 | m.s-1 |
| h | Planck constant | 6.626×10-34 | J.Hz-1 |
| ħ = h/2π | reduced Plank constant | 1.055×10-34 | J.Hz-1 |
| μ0 | magnetic permeability of free space | 1.257×10-6 | N.A-2 |
| Z0 = μ0c | impedance of free space | 377 | Ω |
| ε0 = 1/μ0c2 | permittivity of free space | 8.854×10-12 | F.m-1 |
| k or kB | Boltzman constant | 1.38×10-23 | J.K-1 |
| G | gravitational constant | 6.67×10-11 | m3.kg-1.s-2 |
| σ | Stefan-Boltzman constant | 5.67×10-8 | W.m-2.K-4 |
| e | elementary charge | 1.6×10-19 | C |
| me | electron mass | 9.11×10-31 | kg |
| mp | proton mass | 1.672×10-27 | kg |
| mn | neutron mass | 1.674×10–27 | kg |
| mμ | muon mass | 1.88×10-28 | kg |
| NA | Avogadro constant | 6.022×1023 | unitless |
| R = NA x kB | molar gas constant | 8.314 | unitless |
| g | gravitational field strength | 9.81 | m.s-2 |
| α | Wein constant | 2.90×10-3 | m.K |
| u | atomic mass unit | 1.661×10-27 | kg |
Useful Astronomical Data ⬆
| Mercury | Venus | Earth | Moon | Mars | Jupiter | Saturn | Uranus | Neptune | Pluto | |
|---|---|---|---|---|---|---|---|---|---|---|
| mass (1024kg) | 0.33 | 4.87 | 5.97 | 0.073 | 0.642 | 1898 | 568 | 86.8 | 102 | 0.0130 |
| radius (km) | 2440 | 6052 | 6378 | 1738 | 1967 | 71492 | 60268 | 25559 | 24764 | 1188 |
| density (kgm-3) | 5429 | 5243 | 5514 | 3340 | 3934 | 1326 | 687 | 1270 | 1638 | 1850 |
| g (at surface) | 3.7 | 8.9 | 9.8 | 1.6 | 3.7 | 23.1 | 9.0 | 8.7 | 11.0 | 0.7 |
| vesc (km.s-1) | 4.3 | 10.4 | 11.2 | 2.4 | 5.0 | 59.5 | 35.5 | 21.3 | 23.5 | 1.3 |
| length of day (hrs) | 4222.6 | 2802 | 24 | 708.7 | 24.7 | 9.9 | 10.7 | 17.2 | 16.1 | 153.3 |
| sun distance (106km) | 57.9 | 108.2 | 149.6 | 149.9 | 228.0 | 778.5 | 1432 | 2867 | 4515 | 5906.4 |
| Torbital (days) | 88 | 224.7 | 365.2 | 27.3 | 687 | 4331 | 10747 | 30589 | 59800 | 90560 |
| mean temp (C) | 167 | 464 | 15 | -20 | -65 | -110 | -140 | -195 | -200 | -225 |
| no moons | 0 | 0 | 1 | 0 | 2 | 92 | 83 | 27 | 14 | 5 |
The Sun
| mass | 1.9885×1030 | kg |
| radius (equatorial) | 696000 | km |
| age | 4.6×109 | years |
| temperature (surface) | 5500 | C |
| temperature (core) | 14000000 | C |
- Nearest star – Proxima Centauri (red dwarf (m5)) – 4.27 ly
- Nearest main sequence star – Sirius – 8.57 ly
Astronomical Distances
| Astronomical Distance | Description | Distance in km |
| astronomical unit (AU) | earth – sun distance | 1.496×108 |
| light year (ly) | distance traveled at 3×108ms-1 in one year | 9.5×1012 |
| parsec (pc) | distance at which 1AU subtends an angle of 1 arc second | 3.09×1013 (3.26ly) |
Geometrical Equations ⬆
- arc length = rθ
- circumference of circle = 2πr
- area of circle = πr2
- cylindrical area = πr2h
- spherical area = 4πr2
- spherical volume = 4/3 πr3
Thermal Physics ⬆
| Quantity | C (J.kg-1.K-1) | Lf (J.kg-1) | Lv (J.kg-1) |
| ice | 2100 | 3.36×105 | |
| water | 4200 | 2.3×106 | |
| copper | 390 | 20.7×104 | |
| lead | 130 | 2.32×104 | |
| concrete | 850 |
Particle Physics ⬆
| Class | Name | Symbol | Rest Mass Energy (MeV) | Force Interaction | Quark Composition |
| photon | photon | γ | 0 | Electromagnetic | NA |
| lepton | electron neutrino | νe | 0 | weak | NA |
| muon neutrino | νm | 0 | weak | NA | |
| tau neutrino | νt | 0 | weak | NA | |
| electron | e | 0.510999 | weak, electromagnetic | NA | |
| muon | μ | 105.659 | weak, electromagnetic | NA | |
| mesons | pion (pi-meson) | π+ | 139.576 | strong, electromagnetic | up, anti-down |
| π– | 139.576 | strong, electromagnetic | down, anti-up | ||
| π0 | 134.972 | strong | (up, anti-up) or (down , anti-down) or (strange anti-strange) | ||
| kaon (k-meson) | K+ | 493.821 | strong, electromagnetic | up, anti-strange | |
| K– | 493.821 | strong, electromagnetic | strange, anti-up | ||
| K0 | 497.762 | strong | down, anti-strange | ||
| baryons | proton | p | 938.257 | strong, weak, electromagnetic | up, up, down |
| neutron | n | 939.551 | strong, weak | up, down, down |
Quark Properties
| up | down | strange | anti-up | anti-down | anti-strange | |
| charge Q | + 2/3 | – 1/3 | – 1/3 | – 2/3 | + 1/3 | + 1/3 |
| strangeness S | 0 | 0 | -1 | 0 | 0 | +1 |
| baryon number B | + 1/3 | + 1/3 | + 1/3 | – 1/3 | – 1/3 | – 1/3 |
🔬 Why These Constants Matter
Understanding physical constants allows you to:
- Solve numerical exam questions quickly
- Check answers using standard values
- Link topics across physics (e.g. energy, particles, fields)
For example, constants like the speed of light and Planck constant are fundamental in modern physics topics like quantum mechanics and relativity.
📚 How to Revise This Page
- Memorise the most common constants (c, h, e, G)
- Practise applying them in past paper questions
- Use this page as a quick reference sheet before exams