Ok so your understanding is absolutely correct...while people have given quite a few good answers...i would like to present you my point of view... acceleration=dv/dt now dv/dt can be represented as (dv/dx)*(dx/dt) dx/dt=V Thereforce a=vdv/dx adx=vdv of intergarting with resepect to displacement we get v²-u²=2as where s is the displacement Multiply both sides by mass 'm' mv²-mu²=2mas 1/2mv²-1/2mu²=mas mas is now defined as work 'W' and 1/2mv²-1/2mu² is defined as change in kinetic energy KE This is the derviation of the famous work energy theorem.....I hope this helps you