How can we derive Newtown's first …

Newton's 1st law from 2nd law- According to newton's 2nd law F=ma If no force is applied F=0 ma=0 Since m is not equal to 0 Therefore a=0 V-U÷t=0 V-U=0 V=U It means the body in the state of rest remains in state of rest and if the body is in uniform motion remains in uniform motion when applied force is zero. Hence the 1st law is verified. Newton's 3rd law from 2nd law - Suppose, two bodies having momentum P1 and P2 collide with each other. Hence from the "law of conservation of momentum " we know that- P1+P2=K (constant) Differentiating this equation with respect to 't'(time)- dP1÷dt + dP2÷dt = dK÷dt dP1÷dt + dP2÷dt = 0 ( since differentiation of constant term is 0) dP1÷dt = dP2÷dt F1 = -F2 (F is force) Hence, the 3rd law is verified. -by Manik Ranjan