Igcse Physics Formula

www.educatalyst.net Baaz Pathan IGCSE/IB Tutors JUHU 9930758555 Useful Formulas for the IGCSE Physical Science Examinations General Physics Formula in Symbols Formula in Words v = d /t speed = total distance /total time w = m x g weight = mass x acceleration of gravity a = v /t acceleration = change in speed /change in time d = m /v density = mass /volume F = m x a force = mass x acceleration x = k x F extension = a constant x load W = F x d work = force x distance p.e. = m x g x h potential energy = mass x acceleration of gravity x height k.e. = ½ x m x v2 kinetic energy = ½ x mass x velocity squared e = Eout /Ein x 100% energy efficiency = energy output /energy input x 100% E = W energy used = work done E = m x c2 energy of a nuclear reaction = mass x speed of light squared P = E /t power = energy /time Physics of Waves Formula in Symbols Formula in Words c = f x  speed of a wave = frequency x wavelength i = r angle of incidence = angle of reflection n = sin i /sin r index of refraction = sine of incident angle /sine of refracted angle Electricity and Magnetism Formula in Symbols Formula in Words I = Q /t current = charge /time R = V /I resistance = potential difference /current R = k x l /A resistance = a constant x length /cross sectional area R = R1 + R2 resistances in series add together 1 /R = 1 /R1 + 1 /R2 reciprocals of resistances in parallel add together I = I1 + I2 currents in parallel add together Iin = Iout total current into a point = total current out of a point V = V1 + V2 voltage of source = sum of all voltage drops in a circuit P = I x V power used in an electric circuit = current x voltage E = I x V x t energy used in an electric circuit = current x voltage x time Vp = Np voltage in primary coil = number of turns in primary coil Vs = Ns voltage in secondary coil number of turns in secondary coil Vp x Ip = Vs x Is power in primary coil = power in secondary coil (for a perfect transformer) V = w/Q Q = I t W = V x I x t P = V x I P = I2 x R P = V2 /R Sp Heat Capacity Q = m x c x ∆ t P t = m x c x ∆ t V I t = m x c x ∆ t Thermal Capacity = m x C Or = Q /∆ t Sp Latent Heat of Fusion Q = m X Lf or P t = m x Lf VIt = m X Lf Sp Latent Heat of Vaporisation Q = m x Lv or Pt = m x Lv V I t = m x Lv