IGCSE CIE Physics 0625 (2020) Formula List - PDF

iGCSE CIE Physics 0625 (2020 Syllabus) Formula List General Average speed (ms-1) = distance (m) time (s) Average velocity (ms-1) = displacement (m) v=s time (s)...

iGCSE CIE Physics 0625 (2020 Syllabus) Formula List General Average speed (ms-1) = distance (m) time (s) Average velocity (ms-1) = displacement (m) v=s time (s) t Period of a pendulum (s) = total time (s) T= t number of swings number Acceleration (ms-2) = final velocity (ms-1) – initial velocity (ms-1) a = v-u time (s) t Weight (N) = mass (kg) × gravitational field strength (ms-2) F = mg Note: Earth’s gravitational field strength = 10 ms-2 Force (N) = mass (kg) × acceleration (ms-2) F = ma -3 Density (kgm ) = mass (kg) ρ=M volume (m3) V Hooke’s law: Force (N) = constant (Nm-1) × extension (m) F = kx Pressure (Pa) = force (N) P=F area (m2) A Fluid Pressure (Pa) = density (kgm-3) × gravitational field strength (ms-2 or Nkg-1) × height (m) P = ρgh Work (J) = force (N) × distance moved (m) ΔE = Fd Power (W) = work (J) P = ΔE time (s) t Kinetic Energy (J) = ½ × mass (kg) × velocity2 (ms-1) KE = ½mv2 Gravitational potential energy (J) GPE = mgh = mass (kg) × gravitational field strength (ms-2 or Nkg-1) × height (m) Efficiency (%) = useful power output (W) × 100 Efficiency = Pout total power input (W) Pin Efficiency (%) = useful energy output (J) × 100 Efficiency = Eout total energy input (J) Ein Moment (Nm) = force (N) × perpendicular distance from pivot (m) M = Fd Sum of clockwise moments (Nm) = sum of anticlockwise moments (Nm) F1d1 = F2d2 -1 -1 Momentum (kgms ) = mass (kg) × velocity (ms ) p = mv -1 Force (N) = change in momentum (kgms ) F = Δp time (s) t Impulse (kgms-1 or Ns) = change in momentum (kgms-1) Ft = mv -mu 2 -1 Centripetal Force (N) = mass (kg) × velocity (ms ) F = mv2 radius (m) r Orbital Period (s) = 2 × π × radius (m) T = 2πr velocity (ms-1) v Thermal Boyle’s Law for changes in gas pressure at constant temperature : P1V1 = P2V2 pressure1 (Pa) × volume1 (m3) = pressure2 (Pa)× volume2 (m3) or or PV = constant pressure (Pa) × volume (m3) = constant Energy (J) = mass (kg) × specific heat capacity (Jkg-1°C-1) × temperature change (°C) E = mcΔT -1 -1 -1 Thermal capacity (J°C ) = mass (kg) × specific heat capacity (Jkg °C ) C = mc -1 Energy transferred (J) = mass (kg) × specific latent heat (Jkg ) E = ml -1 Expansion (m) = linear expansivity (°C ) × original length (m) × temperature rise (°C) Expansion = αlΔT Electricity Current (A) = charge (C) I=Q time (s) t Voltage (V) = energy transferred (J) V=E charge (C) Q Voltage (V) = current (A) × resistance (Ω) V = IR Power (W) = current (A) × voltage (V) P = IV 2 Power (W) = current (A) × resistance (Ω) P = I2R Energy transferred (J) = current (A) × voltage (V) × time (s) ΔE = IVt Energy transferred (J) = power (W) × time (s) ΔE = Pt Resistors in series: Total Resistance (Ω) = sum of individual resistors (Ω) RTOTAL = R1+R2+R3+...Rn Resistors in parallel: 1 = 1 total resistance (Ω) sum of individual resistors (Ω) Resistance (Ω) = resistivity (Ωm) × length (m) R = ρl area (m2) A Note: since wires have a circular cross section, area = π × radius 2 Transformers: voltage in secondary coil (V) = turns on secondary coil Vs = Ns voltage in primary coil (V) turns on primary coil Vp Np Transformers: voltage in primary coil (V) = current in secondary coil (A) Vp = Is voltage in secondary coil (V) current in primary coil (A) Vs Ip Waves Wave speed (ms-1) = frequency (Hz) × wavelength (m) c = fλ Frequency (Hz) = 1 F=1 Period (s) T Refractive index = sine of the angle of incidence, i n = sini sine of the angle of refraction, r sinr Refractive index = speed of light in vacuum n = cv speed of light in material cm Refractive index = 1‌‌ n= 1 sine of critical angle sinc Nuclear Radioactive alpha decay: Radioactive beta decay: Radioactive gamma decay: Energy (J) = mass defect (kg) × speed of light2 (ms-1) E = mc2 Compiled by J.Wilson January 2020