Notes aligned to 2026–2028 Physics IGCSE Syllabus
Unit One: Motion, Forces & Energy
Unit Four: Electricity & Magnetism
| $10^9$ | G | Giga |
|---|---|---|
| $10^6$ | M | Mega |
| $10^3$ | k | Kilo |
| $10^{-2}$ | c | Centi |
| $10^{-3}$ | m | Milli |
| $10^{-6}$ | μ | Micro |
| $10^{-9}$ | n | Nano |
| m/s | $s=d/t$ | speed = distance [m] / time [s] |
|---|---|---|
| m/s² | $a= v-u / ∆t$ | |
| acceleration (1) = ∆ velocity [m/s] / ∆ time [s] | ||
| m/s² | $a = ∆v / ∆t$ | acceleration (1) = ∆ velocity [m/s] / ∆ time [s] |
| N/kg | $g=W/m$ | |
| gravitational field strength = force [N] / mass [kg] | ||
| N | $W=m*g$ | |
| weight or force = mass [kg] x gravitational field strength [N/kg] | ||
| kg/m³ | $p=m/V$ | density = mass [kg] / volume [m³] |
| N/m | $k=F/x$ | spring constant = force [N] / extension of the spring from its original state [m] |
| N | $F = m*a$ | resultant force (1) = mass [kg] x acceleration [m/s²] |
| N | $a=F/m$ | aceleration (2) = resultant force [m/s²] / mass [kg] |
| Nm | $M=F*d$ | moment = force [N] x perpendicular distance from the pivot [m] |
| Ns or kg m/s | $p=m*v$ | momentum = mass [kg] x velocity [m/s] |
| Ns or kg m/s | $p=p_1-p_2$ | momentum = momentum before collision [kg m/s] — after collision [kg m/s] |
| Ns or kg m/s | $p=F*t$ | impulse = force [N] x time [s] |
| Ns or kg m/s | $p=mv-mu$ | impulse = (mass x final velocity) — (mass x initial velocity) |
| N | $F=∆p/∆t$ | resultant force (2) = ∆ momentum [Ns or kg m/s] / ∆ time [s] |
| Nm or J | $KE=(mv^2)/2$ | kinetic energy = ( mass [kg] x velocity² [m/s] ) / 2 |
| Nm or J | $GPE=mg ∆h$ | gravitational potential energy = mass [kg] x gravitational field strength [N/kg] x ∆ height [m] |
| Nm or J | $W=F*d$ | work = force [N] x distance [m] |
| W | $P=W/t$ | power = work [Nm or J] / time [s] |
| N/m² or Pa | $P=F/A$ | pressure (1) = force [N] / area [m²] |
| N/m² or Pa | $P=pg∆h$ | pressure (2) = density [kg/m³] x gravirational field strength [N/kg] x height [m] |
| Efficiency % | $\frac{useful.output}{total.input} * 100$ | percentage of efficiency (1) = ( useful energy output / total energy input ) x 100 |
| percentage of efficiency (2) = ( useful power output / total power input ) x 100 | ||
| percentage of efficiency (3) = ( useful work output / total work input ) x 100 |
| Pascals (Pa) | $p=F/A$ | pressure = force [N] / area [m²] |
|---|---|---|
| Pascals (Pa) | $p=k(1)/v$ | pressure (1) = constant / volume [m³] |
| $p_1V_1=p_2V_2$ | pressure_1 [Pa] x volume_1 [m³] = pressure_2 [Pa] x volume_2 [m³] | |
| $pV=k$ | constant = pressure [Pa] x volume [m³] | |
| Joules (J) | $E= MCΔθ$ | energy = mass [kg] x heat capacity [J/kg °C] x Δ temperature [°C] |
| m/s | $v=fλ$ | velocity = frequency [Hz] x distance [m] |
|---|---|---|
| Hertz (Hz) | $f=1/t$ | frequency = 1 / time [s] |
| $n=sin(i)/sin(r)$ | refractive index (1) = sin incident angle / sin refractive angle | |
| $n_1sin(i)=n_2sin(r)$ | refractive index_1 x sin incident angle = refractive index_2 x sin refractive angle | |
| $n= 3\times10^8/speed.med$ | refractive index (2) = speed of light in vacumm; 3 x 10⁸ m/s / speed of light in a medium [m/s] | |
| $n=1/sin(c)$ | refractive index, internally (3) = 1 / sin critical angle | |
| Meters (m) | $d=1/2*vt$ | echolocation distance = 1/2 x speed of sound [m/s] x time [s] |
| Amps (A) | $I=Q/t$ | current = charge [C] / time [s] |
|---|---|---|
| Volts (V) | $E~or~V=W/Q$ | electromotive force EMF or potential diff. PD = work [J] / charge [C] |
| Ohms (Ω) | $R=V/I$ | resistance = voltage [V] / current [A] |
| Volts (V) | $V=I*R$ | voltage = current [A] x resistance [Ω] |
| Watts (W) | $P=I*V$ | electrical power = current [A] x voltage [V] |
| Joules (J) | $E=P*t$ | electrical energy (1) = power [W] x time [s] |
| Joules (J) | $E=IVt$ | electrical energy (1) = current [A] x p.d. [V] x time [s] |
| kWh | $E=P*t$ | electrical energy (2) = power [kW] x time [h] |
| Volts (V) | $V_1\;+ V_2\;+ V_3...V_n$ | total voltage (emf) in simple circuit = voltage_1 + voltage_2 + voltage_3… |
| Ohms (Ω) | $R_1\;+ R_2\;+ R_3...R_n$ | total resistance in simple circuit = resistance_1 + resistance_2… |
| Ohms (Ω) | $\frac{1}{R_1}\;+ \frac{1}{R_2}\;+ \frac{1}{R_3}... \frac{1}{R_n}$ | total resistance in parallel circuit = 1 / resistance_1 + 1 / resistance_2… |
| $\frac{V_1}{V_2}=\frac{R_1}{R_2}$ | potential divider (same ratio equation) | |
| $\frac{V_p}{V_s} = \frac{N_p}{N_s}$ | transformers: primary voltage [V] / secondary voltage [V] = | |
| number of coils turn in primary / number of coils turn in secondary | ||
| $P_{input}=P_{output}$ | full efficient transformers: power input [W] = power output [W] | |
| $I_p \times V_p = I_s \times V_s$ | full efficient transformers: primary current [A] x primary voltage [V] = secondary current [A] x secondary voltage [V] | |
| Watts (W) | $P_{loss} = I^2 \times \Omega$ | power loss = current² [A] x resistance [Ω] |
| decays / s | $Count~Rate=\frac{Total~Counts}{Time}$ | Count Rate = Total Counts / Time [s] |
|---|
| s | $t=d/v$ | time = distance [m] / speed of light (3x10⁸) [m/s] |
|---|---|---|
| m/s | $v=\frac{2πr}{T}$ | speed = circumference of orbit [m] / orbital period [s] |
| 1/s | $H_0=\frac{v}{d}$ | hubble constant = velocity of an object moving away [km/s] / distance between [km] |
| $\frac{1}{H_0}=\frac{d}{v}$ | age of universe. |
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