State Newton's second law of motion .
Hence , derive the equation of motion F = ma from it .

Explanation

Newton 's 2nd law : The rate of change of momentum of a body is proportional to external force and acts along the direction of force applied .
i.e, `(dp)/(dt)propF`
Derivation of equation F = ma : According Newton's 2nd law.
`(dvec(p))/(dt)propvec(F)rArrF=k.(dbar(p))/(dt)" " .....(1)`
But `vec(p)` = momentum of the body -`mvec(v)`
`thereforeF-k,(d)/(dt)(mvec(v))rArrkm(dvec(v))/(dt)" " ...(2)`
But `(dvec(v))/(dt)` - Rate of change in velocity = acceleration 'a'.
`thereforeF = ma " " ...(3)`
Here , k = constant ,
The proportional constant is made equal to one , by properly selecting the unit of force
`therefore F=ma`