IGCSE Physics Formulas

Useful Formulas for the IGCSE Physical Science Examinations Formula in Symbols v=d/t w=mxg a=v/t d=m/v F=mxa x=kxF W=Fxd p.e. = m x g x h k.e. = ½ x m x v2 e = Eout / Ein x 100% E=W E = m x c2 P=E/t

General Physics Formula in Words speed = total distance / total time weight = mass x acceleration of gravity acceleration = change in speed / change in time density = mass / volume force = mass x acceleration extension = a constant x load work = force x distance potential energy = mass x acceleration of gravity x height kinetic energy = ½ x mass x velocity squared energy efficiency = energy output / energy input x 100% energy used = work done energy of a nuclear reaction = mass x speed of light squared power = energy / time

Formula in Symbols c=fxλ i=r n = sin i / sin r

Physics of Waves Formula in Words speed of a wave = frequency x wavelength angle of incidence = angle of reflection 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=kxl/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=IxV power used in an electric circuit = current x voltage E=IxVxt 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) Formula in Symbols a = s2 a=lxw a=½xbxh a = π x r2 v = s3 v=lxwxh v = π x r2 x h

Geometry Formula in Words area of a square = length of side squared area of a rectangle = length x width area of a triangle = ½ x base x height area of a circle = Pi x radius squared volume of cube = length of side cubed volume of cuboid = length x width x height volume of cylinder = Pi x radius squared x height

You should be able to solve equations with three variables for any variable. For example, if a = b x c, then b = a / c and c = a / b. Formulas in bold are for core. Other formulas are extended, but they also help for many core questions.