PHYSICS FORMULA

1. SPM Physics 2009.
Speed Distance / Time taken
Velocity Displacement / Time taken
Newton’s First Law of Object will remain moving / rest unless acted by
Motion (Inertia) unbalance fore
Momentum Product of mass and velocity. mv
Conservation of If there’s a collision, initial momentum = final
momentum momentum
Balanced force Do not affect an object’s motion. Eg, Engine speed up
the car, air resistance slow down the car. But the force
is balance. Therefore, car move in constant speed &
direction.
Unbalanced force Affect an object’s motion.
Newton’s Second Law Acceleration directly proportional to net force but
of Motion inversely proportional to mass. F=ma
Impulsive force Rate of change of momentum
Impulse Change in momentum
Equilibrium force Zero net force
Work Product of applied force and displacement. W=Fs
Conservation of energy Energy can transform from one kind to another
Hooke’s Law Force applied to a spring is directly proportional to
spring extension
Pressure Force / Area
Pascal’s Principle Force applied = force produced . FA=FA
Archimedes Principle Buoyant force = Fluid displaced by object
Bernoulli’s Principle When speed increase, pressure decrease
Thermal equilibrium No net heat flow
Specific heat capacity Amount of heat needed to change temperature of 1 kg
by 1 K
Boyle’s Law Pressure increase, volume decrease (inversely
proportional) PV
Charles’ Law Volume increase, temperature increase (directly
proportional) V/T
Pressure Law Pressure increase, temperature increase (directly
proportional) P/T
Damping Oscillating system that loses energy to the surrounding
Reflection of wave Constant frequency, wavelength, speed
Refraction of wave Constant frequency.
Change wavelength and speed.
*in deep area, longer wavelength and less speed
Diffraction of wave Constant frequency, wavelength, speed. Only direction
of propagation changed.
Coherent wave Same wavelength, frequency
Interference Two wave meets
Sound wave AmpLitude – Louder
Frequency – Pitch
Electromagnetic Range of low frequency to high frequency
spectrum
Ohm’s Law Current is directly proportional to potential difference
Circuits Series Circuit Parallel Circuit
Iman’s Property 2009

2. I=I=I I=I+I
V=V+V V=V=V
R=R+R 1/R=1/R+1/R
Electromotive force (V) Work done by cell
Electromagnet Magnet made by winding a coil round a soft iron core.
Magnetic force is produced when current passed thru
the coil.
Induced current When a wire cuts magnetic flux
Lenz’s Law Direction of induced current will opposed
Faraday’s Law Magnitude of induced current is directly proportional to
the rate of cutting the magnetic flux
Direct current Current which flow in one direction
Alternating current Current that flows to and fro in two opposite direction
Thermionic emission Emission of electron when a metal surface is heated
Doping Adding impurities to semiconductor to increase their
conductivity
Rectification Using diode to convert alternating current into direct
current
Capacitor To maintain a steady output voltage. (smoothing the
capacitor)
Transistor Amplify small current
Logic gate Digital circuit that design to make decision
Nucleon number Total proton & neutrons. Known as mass number.
Isotopes Same proton, different nucleon
Radioactivity Natural disintegration of unstable nucleus
Radioisotopes Unstable isotopes that give out radioactivity emissions
Nuclear fission Splitting a heavy nucleus into two lighter nuclei
Nuclear fusion Combining of two lighter nuclei to form heavier nucleus
Iman’s Property 2009